diff --git a/backend/alembic/versions/006_add_player_positions_to_roster_links.py b/backend/alembic/versions/006_add_player_positions_to_roster_links.py
new file mode 100644
index 0000000..3cc32cf
--- /dev/null
+++ b/backend/alembic/versions/006_add_player_positions_to_roster_links.py
@@ -0,0 +1,33 @@
+"""add player_positions to roster_links
+
+Revision ID: 006
+Revises: 62bd3195c64c
+Create Date: 2026-01-17
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects.postgresql import JSONB
+
+
+# revision identifiers, used by Alembic.
+revision: str = '006'
+down_revision: Union[str, None] = '62bd3195c64c'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # Add player_positions column for storing player's natural positions
+    # This allows the frontend to filter bench players by position type (batters vs pitchers)
+    # Example values: ["SS", "2B", "3B"] or ["SP", "RP"] or ["SP", "DH"] (two-way player)
+    op.add_column(
+        'roster_links',
+        sa.Column('player_positions', JSONB, nullable=True, server_default='[]')
+    )
+
+
+def downgrade() -> None:
+    op.drop_column('roster_links', 'player_positions')
diff --git a/backend/alembic/versions/007_add_player_data_to_roster_links.py b/backend/alembic/versions/007_add_player_data_to_roster_links.py
new file mode 100644
index 0000000..bf76398
--- /dev/null
+++ b/backend/alembic/versions/007_add_player_data_to_roster_links.py
@@ -0,0 +1,31 @@
+"""Add player_data JSONB column to roster_links for caching player names/images.
+
+Revision ID: 007
+Revises: 006
+Create Date: 2026-01-17
+
+This stores player name, image, and headshot at lineup submission time,
+eliminating the need for runtime API calls when loading bench players.
+"""
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects.postgresql import JSONB
+
+
+# revision identifiers, used by Alembic.
+revision = "007"
+down_revision = "006"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "roster_links",
+        sa.Column("player_data", JSONB, nullable=True, server_default="{}")
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("roster_links", "player_data")
diff --git a/backend/app/api/routes/games.py b/backend/app/api/routes/games.py
index 6fc5db7..eb6000d 100644
--- a/backend/app/api/routes/games.py
+++ b/backend/app/api/routes/games.py
@@ -771,6 +771,12 @@ async def submit_lineups(game_id: str, request: SubmitLineupsRequest):
         )
 
 
+class BenchPlayerRequest(BaseModel):
+    """Single bench player in lineup request"""
+
+    player_id: int = Field(..., description="SBA player ID")
+
+
 class SubmitTeamLineupRequest(BaseModel):
     """Request model for submitting a single team's lineup"""
 
@@ -778,6 +784,9 @@ class SubmitTeamLineupRequest(BaseModel):
     lineup: list[LineupPlayerRequest] = Field(
         ..., min_length=9, max_length=10, description="Team's starting lineup (9-10 players)"
     )
+    bench: list[BenchPlayerRequest] = Field(
+        default_factory=list, description="Bench players (not in starting lineup)"
+    )
 
     @field_validator("lineup")
     @classmethod
@@ -1062,7 +1071,49 @@ async def submit_team_lineup(game_id: str, request: SubmitTeamLineupRequest):
                 detail=f"Lineup already submitted for team {request.team_id}"
             )
 
-        # Process lineup
+        # Step 1: Collect all player IDs (starters + bench) for batch API fetch
+        all_player_ids = [p.player_id for p in request.lineup]
+        all_player_ids.extend([p.player_id for p in request.bench])
+
+        # Step 2: Fetch all player data from SBA API to get positions
+        player_data = {}
+        if all_player_ids:
+            try:
+                player_data = await sba_api_client.get_players_batch(all_player_ids)
+                logger.info(f"Fetched {len(player_data)}/{len(all_player_ids)} players from SBA API")
+            except Exception as e:
+                logger.warning(f"Failed to fetch player data from SBA API: {e}")
+                # Continue - roster entries will have empty positions
+
+        # Step 3: Add ALL players to RosterLink with their natural positions and cached data
+        db_ops = DatabaseOperations()
+        roster_count = 0
+        for player_id in all_player_ids:
+            player_positions: list[str] = []
+            cached_player_data: dict | None = None
+
+            if player_id in player_data:
+                player = player_data[player_id]
+                player_positions = player.get_positions()
+                # Cache essential player data to avoid runtime API calls
+                cached_player_data = {
+                    "name": player.name,
+                    "image": player.get_image_url(),
+                    "headshot": player.headshot or "",
+                }
+
+            await db_ops.add_sba_roster_player(
+                game_id=game_uuid,
+                player_id=player_id,
+                team_id=request.team_id,
+                player_positions=player_positions,
+                player_data=cached_player_data,
+            )
+            roster_count += 1
+
+        logger.info(f"Added {roster_count} players to roster for team {request.team_id}")
+
+        # Step 4: Add only STARTERS to active Lineup table
         player_count = 0
         for player in request.lineup:
             await lineup_service.add_sba_player_to_lineup(
@@ -1075,7 +1126,10 @@ async def submit_team_lineup(game_id: str, request: SubmitTeamLineupRequest):
             )
             player_count += 1
 
-        logger.info(f"Added {player_count} players to team {request.team_id} lineup")
+        logger.info(f"Added {player_count} starters to team {request.team_id} lineup")
+
+        # Note: Bench players are NOT added to Lineup - they're derived from
+        # RosterLink players not in active Lineup via get_bench_players()
 
         # Load lineup from DB and cache in state_manager for subsequent checks
         team_lineup = await lineup_service.load_team_lineup_with_player_data(
diff --git a/backend/app/database/operations.py b/backend/app/database/operations.py
index 75c718f..f995718 100644
--- a/backend/app/database/operations.py
+++ b/backend/app/database/operations.py
@@ -290,12 +290,12 @@ class DatabaseOperations:
                 position=position,
                 batting_order=batting_order,
                 is_starter=is_starter,
-                is_active=True,
+                is_active=is_starter,  # Bench players (is_starter=False) are inactive
             )
             session.add(lineup)
             await session.flush()
             await session.refresh(lineup)
-            logger.debug(f"Added SBA player {player_id} to lineup in game {game_id}")
+            logger.debug(f"Added SBA player {player_id} to lineup in game {game_id} (active={is_starter})")
             return lineup
 
     async def get_active_lineup(self, game_id: UUID, team_id: int) -> list[Lineup]:
@@ -325,6 +325,35 @@ class DatabaseOperations:
             )
             return lineups
 
+    async def get_full_lineup(self, game_id: UUID, team_id: int) -> list[Lineup]:
+        """
+        Get full lineup for team including bench players.
+
+        Args:
+            game_id: Game identifier
+            team_id: Team identifier
+
+        Returns:
+            List of all Lineup models (active + bench), active sorted by batting order first
+        """
+        async with self._get_session() as session:
+            result = await session.execute(
+                select(Lineup)
+                .where(
+                    Lineup.game_id == game_id,
+                    Lineup.team_id == team_id,
+                )
+                .order_by(Lineup.is_active.desc(), Lineup.batting_order)
+            )
+            lineups = list(result.scalars().all())
+            active_count = sum(1 for l in lineups if l.is_active)
+            bench_count = len(lineups) - active_count
+            logger.debug(
+                f"Retrieved {len(lineups)} lineup entries for team {team_id} "
+                f"({active_count} active, {bench_count} bench)"
+            )
+            return lineups
+
     async def create_substitution(
         self,
         game_id: UUID,
@@ -640,7 +669,12 @@ class DatabaseOperations:
             )
 
     async def add_sba_roster_player(
-        self, game_id: UUID, player_id: int, team_id: int
+        self,
+        game_id: UUID,
+        player_id: int,
+        team_id: int,
+        player_positions: list[str] | None = None,
+        player_data: dict | None = None,
     ) -> SbaRosterLinkData:
         """
         Add an SBA player to game roster.
@@ -649,6 +683,9 @@ class DatabaseOperations:
             game_id: Game identifier
             player_id: Player identifier
             team_id: Team identifier
+            player_positions: List of natural positions (e.g., ["SS", "2B", "3B"] or ["SP", "RP"])
+                             Used for substitution UI filtering (batters vs pitchers)
+            player_data: Cached player info {name, image, headshot} to avoid runtime API calls
 
         Returns:
             SbaRosterLinkData with populated id
@@ -658,18 +695,27 @@ class DatabaseOperations:
         """
         async with self._get_session() as session:
             roster_link = RosterLink(
-                game_id=game_id, player_id=player_id, team_id=team_id
+                game_id=game_id,
+                player_id=player_id,
+                team_id=team_id,
+                player_positions=player_positions or [],
+                player_data=player_data or {},
             )
             session.add(roster_link)
             await session.flush()
             await session.refresh(roster_link)
-            logger.info(f"Added SBA player {player_id} to roster for game {game_id}")
+            logger.info(
+                f"Added SBA player {player_id} to roster for game {game_id} "
+                f"(positions: {player_positions or []})"
+            )
 
             return SbaRosterLinkData(
                 id=roster_link.id,
                 game_id=roster_link.game_id,
                 player_id=roster_link.player_id,
                 team_id=roster_link.team_id,
+                player_positions=roster_link.player_positions or [],
+                player_data=roster_link.player_data,
             )
 
     async def get_pd_roster(
@@ -717,7 +763,7 @@ class DatabaseOperations:
             team_id: Optional team filter
 
         Returns:
-            List of SbaRosterLinkData
+            List of SbaRosterLinkData with player_positions
         """
         async with self._get_session() as session:
             query = select(RosterLink).where(
@@ -736,10 +782,70 @@ class DatabaseOperations:
                     game_id=link.game_id,
                     player_id=link.player_id,
                     team_id=link.team_id,
+                    player_positions=link.player_positions or [],
+                    player_data=link.player_data,
                 )
                 for link in roster_links
             ]
 
+    async def get_bench_players(
+        self, game_id: UUID, team_id: int
+    ) -> list[SbaRosterLinkData]:
+        """
+        Get bench players for a team (roster players not in active lineup).
+
+        This queries RosterLink for players that are NOT in the active Lineup,
+        including their player_positions for UI filtering (batters vs pitchers).
+
+        Args:
+            game_id: Game identifier
+            team_id: Team identifier
+
+        Returns:
+            List of SbaRosterLinkData for bench players with is_pitcher/is_batter computed
+        """
+        async with self._get_session() as session:
+            # Get player_ids that are in the active lineup
+            active_lineup_query = (
+                select(Lineup.player_id)
+                .where(
+                    Lineup.game_id == game_id,
+                    Lineup.team_id == team_id,
+                    Lineup.is_active == True,
+                    Lineup.player_id.is_not(None),  # SBA players
+                )
+            )
+
+            # Get roster players NOT in active lineup
+            bench_query = (
+                select(RosterLink)
+                .where(
+                    RosterLink.game_id == game_id,
+                    RosterLink.team_id == team_id,
+                    RosterLink.player_id.is_not(None),  # SBA players
+                    RosterLink.player_id.not_in(active_lineup_query),
+                )
+            )
+
+            result = await session.execute(bench_query)
+            bench_links = result.scalars().all()
+
+            logger.debug(
+                f"Retrieved {len(bench_links)} bench players for team {team_id} in game {game_id}"
+            )
+
+            return [
+                SbaRosterLinkData(
+                    id=link.id,
+                    game_id=link.game_id,
+                    player_id=link.player_id,
+                    team_id=link.team_id,
+                    player_positions=link.player_positions or [],
+                    player_data=link.player_data,
+                )
+                for link in bench_links
+            ]
+
     async def remove_roster_entry(self, roster_id: int) -> None:
         """
         Remove a roster entry by ID.
diff --git a/backend/app/models/db_models.py b/backend/app/models/db_models.py
index 3b0904a..6970e1b 100644
--- a/backend/app/models/db_models.py
+++ b/backend/app/models/db_models.py
@@ -43,6 +43,11 @@ class RosterLink(Base):
     SBA League: Uses player_id to track which players are rostered
 
     Exactly one of card_id or player_id must be populated per row.
+
+    The player_positions field stores the player's natural positions from the API
+    for use in substitution UI filtering (batters vs pitchers). This supports
+    two-way players like Shohei Ohtani who have both pitching and batting positions.
+    Example: ["SS", "2B", "3B"] or ["SP", "RP"] or ["SP", "DH"]
     """
 
     __tablename__ = "roster_links"
@@ -60,6 +65,14 @@ class RosterLink(Base):
     player_id = Column(Integer, nullable=True)  # SBA only
     team_id = Column(Integer, nullable=False, index=True)
 
+    # Player's natural positions from API (for substitution UI filtering)
+    # Supports two-way players with both pitching and batting positions
+    player_positions = Column(JSONB, default=list)
+
+    # Cached player data (name, image, headshot) to avoid runtime API calls
+    # Populated at lineup submission time
+    player_data = Column(JSONB, default=dict)
+
     # Relationships
     game = relationship("Game", back_populates="roster_links")
 
diff --git a/backend/app/models/roster_models.py b/backend/app/models/roster_models.py
index c99cf47..c9e6e3e 100644
--- a/backend/app/models/roster_models.py
+++ b/backend/app/models/roster_models.py
@@ -8,7 +8,7 @@ Provides league-specific type-safe models for roster operations:
 from abc import ABC, abstractmethod
 from uuid import UUID
 
-from pydantic import BaseModel, ConfigDict, field_validator
+from pydantic import BaseModel, ConfigDict, computed_field, field_validator
 
 
 class BaseRosterLinkData(BaseModel, ABC):
@@ -62,9 +62,18 @@ class SbaRosterLinkData(BaseRosterLinkData):
 
     Used for SBA league games where rosters are composed of players.
     Players are identified directly by player_id without a card system.
+
+    The player_positions field stores the player's natural positions from the API
+    for use in substitution UI filtering (batters vs pitchers). This supports
+    two-way players like Shohei Ohtani who have both pitching and batting positions.
+
+    The player_data field caches essential SbaPlayer fields (name, image, headshot)
+    to avoid runtime API calls when loading bench players.
     """
 
     player_id: int
+    player_positions: list[str] = []
+    player_data: dict | None = None  # Cached SbaPlayer fields: {name, image, headshot}
 
     @field_validator("player_id")
     @classmethod
@@ -79,6 +88,34 @@ class SbaRosterLinkData(BaseRosterLinkData):
     def get_entity_type(self) -> str:
         return "player"
 
+    # Pitcher positions used for filtering
+    # CP = Closer Pitcher (alternate notation for CL)
+    _PITCHER_POSITIONS: set[str] = {"P", "SP", "RP", "CL", "CP"}
+
+    @computed_field
+    @property
+    def is_pitcher(self) -> bool:
+        """True if player has any pitching position (supports two-way players)
+
+        Examples:
+        - ["SP"] -> True
+        - ["SP", "DH"] -> True (two-way player like Ohtani)
+        - ["CF", "DH"] -> False
+        """
+        return any(pos in self._PITCHER_POSITIONS for pos in self.player_positions)
+
+    @computed_field
+    @property
+    def is_batter(self) -> bool:
+        """True if player has any non-pitching position (supports two-way players)
+
+        Examples:
+        - ["CF", "DH"] -> True
+        - ["SP", "DH"] -> True (two-way player like Ohtani)
+        - ["SP"] -> False (pitcher-only)
+        """
+        return any(pos not in self._PITCHER_POSITIONS for pos in self.player_positions)
+
 
 class RosterLinkCreate(BaseModel):
     """Request model for creating a roster link"""
@@ -87,6 +124,7 @@ class RosterLinkCreate(BaseModel):
     team_id: int
     card_id: int | None = None
     player_id: int | None = None
+    player_positions: list[str] = []  # Natural positions for substitution filtering
 
     @field_validator("team_id")
     @classmethod
@@ -116,5 +154,8 @@ class RosterLinkCreate(BaseModel):
         if self.player_id is None:
             raise ValueError("player_id required for SBA roster")
         return SbaRosterLinkData(
-            game_id=self.game_id, team_id=self.team_id, player_id=self.player_id
+            game_id=self.game_id,
+            team_id=self.team_id,
+            player_id=self.player_id,
+            player_positions=self.player_positions,
         )
diff --git a/backend/app/websocket/handlers.py b/backend/app/websocket/handlers.py
index e063bb8..0320eef 100644
--- a/backend/app/websocket/handlers.py
+++ b/backend/app/websocket/handlers.py
@@ -1394,6 +1394,116 @@ def register_handlers(sio: AsyncServer, manager: ConnectionManager) -> None:
                 sid, "error", {"message": "Invalid lineup request"}
             )
 
+    @sio.event
+    async def get_bench(sid, data):
+        """
+        Get bench players for a team (roster players not in active lineup).
+
+        This queries RosterLink for players that are NOT in the active Lineup,
+        including their natural positions for UI filtering (batters vs pitchers).
+        Supports two-way players with is_pitcher and is_batter computed properties.
+
+        Event data:
+            game_id: UUID of the game
+            team_id: int - team to get bench for
+
+        Emits:
+            bench_data: To requester with bench players including:
+                - player_positions: list of natural positions (e.g., ["SS", "2B"])
+                - is_pitcher: true if player has pitching positions
+                - is_batter: true if player has batting positions
+            error: To requester if validation fails
+        """
+        await manager.update_activity(sid)
+
+        if not await rate_limiter.check_websocket_limit(sid):
+            await manager.emit_to_user(
+                sid, "error", {"message": "Rate limited. Please slow down.", "code": "RATE_LIMITED"}
+            )
+            return
+
+        try:
+            game_id_str = data.get("game_id")
+            if not game_id_str:
+                await manager.emit_to_user(sid, "error", {"message": "Missing game_id"})
+                return
+
+            try:
+                game_id = UUID(game_id_str)
+            except (ValueError, AttributeError):
+                await manager.emit_to_user(
+                    sid, "error", {"message": "Invalid game_id format"}
+                )
+                return
+
+            team_id = data.get("team_id")
+            if team_id is None:
+                await manager.emit_to_user(sid, "error", {"message": "Missing team_id"})
+                return
+
+            # Query bench players from RosterLink (roster players not in active lineup)
+            # Player data (name, image, headshot) is cached in RosterLink - no API call needed
+            db_ops = DatabaseOperations()
+            bench_roster = await db_ops.get_bench_players(game_id, team_id)
+
+            if bench_roster:
+                bench_players = []
+                for roster in bench_roster:
+                    # Use cached player_data from RosterLink (populated at lineup submission)
+                    pdata = roster.player_data or {}
+                    player_name = pdata.get("name", f"Player #{roster.player_id}")
+                    player_image = pdata.get("image", "")
+                    player_headshot = pdata.get("headshot", "")
+
+                    bench_players.append({
+                        "roster_id": roster.id,
+                        "player_id": roster.player_id,
+                        "player_positions": roster.player_positions,
+                        "is_pitcher": roster.is_pitcher,
+                        "is_batter": roster.is_batter,
+                        "player": {
+                            "id": roster.player_id,
+                            "name": player_name,
+                            "image": player_image,
+                            "headshot": player_headshot,
+                            # Include positions for frontend filtering (legacy support)
+                            "pos_1": roster.player_positions[0] if roster.player_positions else None,
+                            "pos_2": roster.player_positions[1] if len(roster.player_positions) > 1 else None,
+                            "pos_3": roster.player_positions[2] if len(roster.player_positions) > 2 else None,
+                        },
+                    })
+
+                await manager.emit_to_user(
+                    sid,
+                    "bench_data",
+                    {
+                        "game_id": str(game_id),
+                        "team_id": team_id,
+                        "players": bench_players,
+                    },
+                )
+                logger.info(
+                    f"Bench data sent for game {game_id}, team {team_id}: {len(bench_players)} players"
+                )
+            else:
+                await manager.emit_to_user(
+                    sid,
+                    "bench_data",
+                    {"game_id": str(game_id), "team_id": team_id, "players": []},
+                )
+                logger.info(f"No bench players found for game {game_id}, team {team_id}")
+
+        except SQLAlchemyError as e:
+            logger.error(f"Database error in get_bench: {e}")
+            await manager.emit_to_user(
+                sid, "error", {"message": "Database error - please retry"}
+            )
+        except (ValueError, TypeError) as e:
+            logger.warning(f"Invalid data in get_bench request: {e}")
+            await manager.emit_to_user(
+                sid, "error", {"message": "Invalid bench request"}
+            )
+
     @sio.event
     async def submit_defensive_decision(sid, data):
         """
diff --git a/backend/tests/integration/database/test_operations.py b/backend/tests/integration/database/test_operations.py
index 9fc8e40..77eedf5 100644
--- a/backend/tests/integration/database/test_operations.py
+++ b/backend/tests/integration/database/test_operations.py
@@ -736,6 +736,141 @@ class TestDatabaseOperationsRoster:
         roster = await db_ops.get_sba_roster(game_id)
         assert len(roster) == 0
 
+    async def test_get_bench_players(self, db_ops, db_session):
+        """
+        Test get_bench_players returns roster players NOT in active lineup.
+
+        This verifies the RosterLink refactor where:
+        - RosterLink contains ALL eligible players with player_positions
+        - Lineup contains only ACTIVE players
+        - Bench = RosterLink players NOT IN Lineup
+
+        Also tests computed is_pitcher/is_batter properties.
+        """
+        game_id = uuid4()
+        team_id = 10
+
+        # Create game
+        await db_ops.create_game(
+            game_id=game_id,
+            league_id="sba",
+            home_team_id=team_id,
+            away_team_id=20,
+            game_mode="friendly",
+            visibility="public"
+        )
+
+        # Add players to RosterLink with player_positions
+        # Player 101: Pitcher only
+        await db_ops.add_sba_roster_player(
+            game_id=game_id,
+            player_id=101,
+            team_id=team_id,
+            player_positions=["SP", "RP"]
+        )
+        # Player 102: Batter only (shortstop)
+        await db_ops.add_sba_roster_player(
+            game_id=game_id,
+            player_id=102,
+            team_id=team_id,
+            player_positions=["SS", "2B"]
+        )
+        # Player 103: Two-way player (pitcher and DH)
+        await db_ops.add_sba_roster_player(
+            game_id=game_id,
+            player_id=103,
+            team_id=team_id,
+            player_positions=["SP", "DH"]
+        )
+        # Player 104: Outfielder (will be in active lineup)
+        await db_ops.add_sba_roster_player(
+            game_id=game_id,
+            player_id=104,
+            team_id=team_id,
+            player_positions=["CF", "RF"]
+        )
+
+        # Add player 104 to ACTIVE lineup (not bench)
+        await db_ops.add_sba_lineup_player(
+            game_id=game_id,
+            team_id=team_id,
+            player_id=104,
+            position="CF",
+            batting_order=1,
+            is_starter=True
+        )
+        await db_session.flush()
+
+        # Get bench players (should be 101, 102, 103 - NOT 104)
+        bench = await db_ops.get_bench_players(game_id, team_id)
+
+        # Verify count
+        assert len(bench) == 3
+
+        # Verify player IDs (104 should NOT be in bench)
+        bench_player_ids = {p.player_id for p in bench}
+        assert bench_player_ids == {101, 102, 103}
+        assert 104 not in bench_player_ids
+
+        # Verify computed properties for each player
+        bench_by_id = {p.player_id: p for p in bench}
+
+        # Player 101: Pitcher only
+        assert bench_by_id[101].is_pitcher is True
+        assert bench_by_id[101].is_batter is False
+        assert bench_by_id[101].player_positions == ["SP", "RP"]
+
+        # Player 102: Batter only
+        assert bench_by_id[102].is_pitcher is False
+        assert bench_by_id[102].is_batter is True
+        assert bench_by_id[102].player_positions == ["SS", "2B"]
+
+        # Player 103: Two-way player (BOTH is_pitcher AND is_batter)
+        assert bench_by_id[103].is_pitcher is True
+        assert bench_by_id[103].is_batter is True
+        assert bench_by_id[103].player_positions == ["SP", "DH"]
+
+    async def test_get_bench_players_empty(self, db_ops, db_session):
+        """
+        Test get_bench_players returns empty list when all roster players are in lineup.
+        """
+        game_id = uuid4()
+        team_id = 10
+
+        # Create game
+        await db_ops.create_game(
+            game_id=game_id,
+            league_id="sba",
+            home_team_id=team_id,
+            away_team_id=20,
+            game_mode="friendly",
+            visibility="public"
+        )
+
+        # Add player to roster
+        await db_ops.add_sba_roster_player(
+            game_id=game_id,
+            player_id=101,
+            team_id=team_id,
+            player_positions=["CF"]
+        )
+
+        # Add same player to active lineup
+        await db_ops.add_sba_lineup_player(
+            game_id=game_id,
+            team_id=team_id,
+            player_id=101,
+            position="CF",
+            batting_order=1,
+            is_starter=True
+        )
+        await db_session.flush()
+
+        # Get bench players (should be empty)
+        bench = await db_ops.get_bench_players(game_id, team_id)
+
+        assert len(bench) == 0
+
 
 class TestDatabaseOperationsRollback:
     """Tests for database rollback operations (delete_plays_after, etc.)"""
diff --git a/frontend-sba/components/Lineup/InlineSubstitutionPanel.vue b/frontend-sba/components/Lineup/InlineSubstitutionPanel.vue
new file mode 100644
index 0000000..6421638
--- /dev/null
+++ b/frontend-sba/components/Lineup/InlineSubstitutionPanel.vue
@@ -0,0 +1,344 @@
+<template>
+  <div class="p-4 space-y-4">
+    <!-- Position Selector -->
+    <PositionSelector
+      v-if="showPositionSelector"
+      :mode="substitutionType"
+      v-model="selectedPosition"
+      :current-position="currentPosition"
+      :label="positionLabel"
+      :required="positionRequired"
+    />
+
+    <!-- Available Players Section -->
+    <div v-if="!isPositionChangeOnly">
+      <div class="text-xs text-gray-400 mb-2">{{ playersLabel }}</div>
+
+      <!-- No players message -->
+      <div v-if="availablePlayers.length === 0" class="text-center py-6 text-gray-500 text-sm">
+        No players available
+      </div>
+
+      <!-- Player Grid -->
+      <div v-else class="grid grid-cols-2 gap-2">
+        <button
+          v-for="benchPlayer in availablePlayers"
+          :key="benchPlayer.roster_id"
+          :class="[
+            'rounded-lg p-2.5 text-left transition-all select-none touch-manipulation',
+            selectedPlayerId === benchPlayer.player_id
+              ? 'bg-green-900/40 border-green-600/50 border ring-2 ring-green-500/30'
+              : 'bg-gray-700/60 hover:bg-green-900/40 border border-transparent hover:border-green-600/50'
+          ]"
+          @click="selectPlayer(benchPlayer)"
+        >
+          <div class="flex items-center gap-2">
+            <div
+              :class="[
+                'w-8 h-8 rounded-full flex items-center justify-center text-xs font-bold',
+                selectedPlayerId === benchPlayer.player_id
+                  ? 'bg-gradient-to-br from-green-700 to-green-800'
+                  : 'bg-gradient-to-br from-gray-600 to-gray-700'
+              ]"
+            >
+              <template v-if="selectedPlayerId === benchPlayer.player_id">
+                ✓
+              </template>
+              <template v-else>
+                {{ getInitials(benchPlayer.player.name) }}
+              </template>
+            </div>
+            <div>
+              <div class="font-medium text-sm">{{ benchPlayer.player.name }}</div>
+              <div :class="[
+                'text-[10px]',
+                selectedPlayerId === benchPlayer.player_id ? 'text-green-400' : 'text-gray-400'
+              ]">
+                {{ formatPositions(benchPlayer) }}
+              </div>
+            </div>
+          </div>
+        </button>
+      </div>
+    </div>
+
+    <!-- Emergency Players (Pitchers for defensive subs) -->
+    <div v-if="showEmergencySection && emergencyPlayers.length > 0">
+      <button
+        class="w-full flex items-center justify-between text-xs text-gray-500 hover:text-gray-400 py-2 border-t border-gray-700/50 transition-colors select-none"
+        @click="showEmergency = !showEmergency"
+      >
+        <span>
+          <span class="mr-1">{{ showEmergency ? '▼' : '▶' }}</span>
+          Show Pitchers
+          <span class="text-amber-500">(emergency)</span>
+        </span>
+        <span class="bg-gray-700 px-1.5 py-0.5 rounded text-gray-400">
+          {{ emergencyPlayers.length }}
+        </span>
+      </button>
+
+      <div v-if="showEmergency" class="grid grid-cols-2 gap-2 mt-2">
+        <button
+          v-for="benchPlayer in emergencyPlayers"
+          :key="benchPlayer.roster_id"
+          :class="[
+            'rounded-lg p-2.5 text-left transition-all select-none touch-manipulation',
+            selectedPlayerId === benchPlayer.player_id
+              ? 'bg-amber-900/40 border-amber-600/50 border'
+              : 'bg-amber-900/20 hover:bg-amber-900/40 border border-amber-700/30'
+          ]"
+          @click="selectPlayer(benchPlayer)"
+        >
+          <div class="flex items-center gap-2">
+            <div class="w-8 h-8 rounded-full bg-gradient-to-br from-amber-700 to-amber-800 flex items-center justify-center text-xs font-bold">
+              {{ getInitials(benchPlayer.player.name) }}
+            </div>
+            <div>
+              <div class="font-medium text-sm text-amber-200">{{ benchPlayer.player.name }}</div>
+              <div class="text-[10px] text-amber-400">{{ formatPositions(benchPlayer) }}</div>
+            </div>
+          </div>
+        </button>
+      </div>
+    </div>
+
+    <!-- Position Change Confirm Button -->
+    <button
+      v-if="isPositionChangeOnly"
+      :disabled="!canSubmit"
+      :class="[
+        'w-full py-2.5 font-semibold rounded-lg transition-colors select-none touch-manipulation',
+        canSubmit
+          ? 'bg-blue-600 hover:bg-blue-500 text-white'
+          : 'bg-gray-700 text-gray-500 cursor-not-allowed'
+      ]"
+      @click="handleSubmit"
+    >
+      Confirm Position Change
+    </button>
+
+    <!-- Substitution Submit (auto-submits when player selected for non-defensive) -->
+    <div
+      v-if="!isPositionChangeOnly && substitutionType === 'defensive_replacement' && selectedPlayerId"
+      class="pt-2"
+    >
+      <button
+        :disabled="!canSubmit"
+        :class="[
+          'w-full py-2.5 font-semibold rounded-lg transition-colors select-none touch-manipulation',
+          canSubmit
+            ? 'bg-green-600 hover:bg-green-500 text-white'
+            : 'bg-gray-700 text-gray-500 cursor-not-allowed'
+        ]"
+        @click="handleSubmit"
+      >
+        Confirm Substitution
+      </button>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref, computed, watch } from 'vue'
+import type { BenchPlayer } from '~/types'
+import PositionSelector from './PositionSelector.vue'
+
+type SubstitutionType = 'pinch_hitter' | 'pinch_runner' | 'defensive_replacement' | 'relief_pitcher' | 'position_change'
+
+interface Props {
+  substitutionType: SubstitutionType
+  benchPlayers: BenchPlayer[]
+  currentPosition?: string | null
+  teamId: number
+  playerOutLineupId: number
+}
+
+const props = withDefaults(defineProps<Props>(), {
+  currentPosition: null,
+})
+
+const emit = defineEmits<{
+  submit: [payload: {
+    playerOutLineupId: number
+    playerInCardId?: number
+    newPosition: string
+    teamId: number
+    type: SubstitutionType
+  }]
+}>()
+
+// Local state
+const selectedPosition = ref<string | null>(getDefaultPosition())
+const selectedPlayerId = ref<number | null>(null)
+const showEmergency = ref(false)
+
+// Helper to get default position based on substitution type
+function getDefaultPosition(): string | null {
+  switch (props.substitutionType) {
+    case 'pinch_hitter':
+      return 'PH'
+    case 'pinch_runner':
+      return 'PR'
+    case 'relief_pitcher':
+      return 'P'
+    case 'defensive_replacement':
+      return null // Required selection
+    case 'position_change':
+      return null
+    default:
+      return null
+  }
+}
+
+// Is this a position change only (no player selection)?
+const isPositionChangeOnly = computed(() => props.substitutionType === 'position_change')
+
+// Should we show position selector?
+const showPositionSelector = computed(() => {
+  // Always show for position change
+  if (props.substitutionType === 'position_change') return true
+  // Don't show for relief pitcher (fixed to P)
+  if (props.substitutionType === 'relief_pitcher') return false
+  // Show for everything else
+  return true
+})
+
+// Position selector label
+const positionLabel = computed(() => {
+  if (props.substitutionType === 'position_change') {
+    return 'Change position to:'
+  }
+  return 'Position for new player:'
+})
+
+// Is position required?
+const positionRequired = computed(() => {
+  return props.substitutionType === 'defensive_replacement'
+})
+
+// Players label
+const playersLabel = computed(() => {
+  switch (props.substitutionType) {
+    case 'relief_pitcher':
+      return 'Available Relievers:'
+    case 'defensive_replacement':
+      return 'Available Position Players:'
+    case 'pinch_hitter':
+      return 'Available Batters:'
+    case 'pinch_runner':
+      return 'Available Runners:'
+    default:
+      return 'Available Players:'
+  }
+})
+
+// Show emergency section for defensive replacements and pinch hitters
+const showEmergencySection = computed(() => {
+  return props.substitutionType === 'defensive_replacement' ||
+         props.substitutionType === 'pinch_hitter'
+})
+
+// Filter available players based on substitution type
+// Uses is_pitcher/is_batter computed properties from backend
+// Supports two-way players (is_pitcher=true AND is_batter=true)
+const availablePlayers = computed(() => {
+  switch (props.substitutionType) {
+    case 'relief_pitcher':
+      // Only show players with pitching positions
+      return props.benchPlayers.filter(p => p.is_pitcher)
+    case 'defensive_replacement':
+    case 'pinch_hitter':
+      // Show players with batting positions (includes two-way players)
+      return props.benchPlayers.filter(p => p.is_batter)
+    default:
+      // Show all bench players
+      return props.benchPlayers
+  }
+})
+
+// Emergency players (pitcher-only players for pinch hitters/defensive subs)
+// These are pitchers who DON'T have batting positions (not two-way players)
+const emergencyPlayers = computed(() => {
+  if (props.substitutionType !== 'defensive_replacement' &&
+      props.substitutionType !== 'pinch_hitter') return []
+  // Show pitcher-only players (is_pitcher=true but is_batter=false)
+  return props.benchPlayers.filter(p => p.is_pitcher && !p.is_batter)
+})
+
+// Can submit the substitution?
+const canSubmit = computed(() => {
+  if (props.substitutionType === 'position_change') {
+    return selectedPosition.value !== null && selectedPosition.value !== props.currentPosition
+  }
+
+  if (props.substitutionType === 'defensive_replacement') {
+    return selectedPosition.value !== null && selectedPlayerId.value !== null
+  }
+
+  // For PH/PR/relief, position has default, just need player
+  return selectedPlayerId.value !== null
+})
+
+// Get player initials
+function getInitials(name: string): string {
+  const parts = name.split(' ')
+  if (parts.length >= 2) {
+    return parts[0][0] + parts[parts.length - 1][0]
+  }
+  return name.substring(0, 2).toUpperCase()
+}
+
+// Format positions for display
+// Uses player_positions array from backend (populated from RosterLink)
+function formatPositions(benchPlayer: BenchPlayer): string {
+  if (benchPlayer.player_positions && benchPlayer.player_positions.length > 0) {
+    return benchPlayer.player_positions.slice(0, 3).join(', ')
+  }
+  return 'N/A'
+}
+
+// Select a player
+function selectPlayer(benchPlayer: BenchPlayer) {
+  selectedPlayerId.value = benchPlayer.player_id
+
+  // For non-defensive subs with default position, auto-submit
+  if (props.substitutionType !== 'defensive_replacement' &&
+      props.substitutionType !== 'position_change' &&
+      selectedPosition.value) {
+    handleSubmit()
+  }
+}
+
+// Submit the substitution
+function handleSubmit() {
+  if (!canSubmit.value) return
+
+  const payload: {
+    playerOutLineupId: number
+    playerInCardId?: number
+    newPosition: string
+    teamId: number
+    type: SubstitutionType
+  } = {
+    playerOutLineupId: props.playerOutLineupId,
+    newPosition: selectedPosition.value!,
+    teamId: props.teamId,
+    type: props.substitutionType,
+  }
+
+  // Include player ID for actual substitutions (not position changes)
+  if (!isPositionChangeOnly.value && selectedPlayerId.value) {
+    payload.playerInCardId = selectedPlayerId.value
+  }
+
+  emit('submit', payload)
+}
+
+// Reset position when substitution type changes
+watch(() => props.substitutionType, () => {
+  selectedPosition.value = getDefaultPosition()
+  selectedPlayerId.value = null
+  showEmergency.value = false
+})
+</script>
diff --git a/frontend-sba/components/Lineup/LineupSlotRow.vue b/frontend-sba/components/Lineup/LineupSlotRow.vue
new file mode 100644
index 0000000..08f3b9a
--- /dev/null
+++ b/frontend-sba/components/Lineup/LineupSlotRow.vue
@@ -0,0 +1,205 @@
+<template>
+  <div
+    :class="[
+      'rounded-lg border mb-1.5 transition-all',
+      containerClass
+    ]"
+  >
+    <!-- Slot Header Row -->
+    <div class="flex items-center gap-3 p-2.5">
+      <!-- Order Number / Position Badge -->
+      <div :class="['w-8 h-8 rounded-lg flex items-center justify-center', badgeClass]">
+        <span class="text-sm font-bold">{{ displayBadge }}</span>
+      </div>
+
+      <!-- Player Avatar -->
+      <div
+        :class="[
+          'w-9 h-9 rounded-full flex items-center justify-center text-sm font-bold',
+          avatarClass
+        ]"
+      >
+        <img
+          v-if="player.player.headshot"
+          :src="player.player.headshot"
+          :alt="player.player.name"
+          class="w-full h-full rounded-full object-cover"
+        >
+        <span v-else>{{ initials }}</span>
+      </div>
+
+      <!-- Player Info -->
+      <div class="flex-1 min-w-0">
+        <div class="font-medium text-sm truncate">{{ player.player.name }}</div>
+        <div :class="['text-xs', subtextClass]">
+          {{ player.position }}
+          <template v-if="statusText">
+            <span class="mx-1">{{ statusText }}</span>
+          </template>
+        </div>
+      </div>
+
+      <!-- Action Buttons -->
+      <template v-if="showActions && !isExpanded">
+        <button
+          class="px-3 py-1.5 text-xs font-medium bg-gray-700 hover:bg-gray-600 rounded-lg transition-colors select-none touch-manipulation"
+          @click="$emit('substitute')"
+        >
+          {{ substituteLabel }}
+        </button>
+        <button
+          v-if="showPositionChange"
+          class="px-2 py-1.5 text-xs font-medium bg-gray-700 hover:bg-gray-600 rounded-lg transition-colors select-none touch-manipulation"
+          title="Change Position"
+          @click="$emit('changePosition')"
+        >
+          ✎
+        </button>
+      </template>
+
+      <!-- Cancel Button (when expanded) -->
+      <button
+        v-if="isExpanded"
+        class="px-3 py-1.5 text-xs font-medium bg-red-900/50 hover:bg-red-900/70 text-red-300 rounded-lg transition-colors select-none touch-manipulation"
+        @click="$emit('cancel')"
+      >
+        Cancel
+      </button>
+    </div>
+
+    <!-- Slot for expanded content (accordion) -->
+    <div
+      v-if="isExpanded"
+      class="border-t border-gray-700/50"
+    >
+      <slot name="expanded" />
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { computed } from 'vue'
+import type { Lineup } from '~/types'
+
+type SlotState = 'normal' | 'at_bat' | 'on_base' | 'expanded' | 'position_change'
+
+interface Props {
+  player: Lineup
+  battingOrder?: number | null
+  state?: SlotState
+  isExpanded?: boolean
+  showActions?: boolean
+  showPositionChange?: boolean
+  substituteLabel?: string
+  isPitcher?: boolean
+  basePosition?: '1B' | '2B' | '3B' | null  // For runners on base display
+}
+
+const props = withDefaults(defineProps<Props>(), {
+  battingOrder: null,
+  state: 'normal',
+  isExpanded: false,
+  showActions: true,
+  showPositionChange: true,
+  substituteLabel: 'Substitute',
+  isPitcher: false,
+  basePosition: null,
+})
+
+defineEmits<{
+  substitute: []
+  changePosition: []
+  cancel: []
+}>()
+
+// Compute initials for avatar fallback
+const initials = computed(() => {
+  const parts = props.player.player.name.split(' ')
+  if (parts.length >= 2) {
+    return parts[0][0] + parts[parts.length - 1][0]
+  }
+  return props.player.player.name.substring(0, 2).toUpperCase()
+})
+
+// Display badge (order number or base position)
+const displayBadge = computed(() => {
+  if (props.basePosition) {
+    return props.basePosition
+  }
+  if (props.isPitcher) {
+    return 'P'
+  }
+  return props.battingOrder ?? props.player.batting_order ?? '?'
+})
+
+// Container styling based on state
+const containerClass = computed(() => {
+  if (props.isExpanded) {
+    if (props.state === 'position_change') {
+      return 'bg-gray-800/60 border-blue-500/50 ring-2 ring-blue-500/30'
+    }
+    return 'bg-gray-800/60 border-amber-500/50 ring-2 ring-amber-500/30'
+  }
+
+  switch (props.state) {
+    case 'at_bat':
+      return 'bg-gray-800/60 border-amber-500/50 ring-2 ring-amber-500/30'
+    case 'on_base':
+      return 'bg-gray-800/60 border-green-700/50'
+    default:
+      return 'bg-gray-800/60 border-gray-700/50'
+  }
+})
+
+// Badge styling
+const badgeClass = computed(() => {
+  if (props.basePosition) {
+    return 'bg-green-800/50 text-green-400'
+  }
+  if (props.isPitcher) {
+    return 'bg-blue-900/50 text-blue-400'
+  }
+
+  switch (props.state) {
+    case 'at_bat':
+      return 'bg-amber-900/50 text-amber-400'
+    default:
+      return 'bg-gray-700/50 text-gray-400'
+  }
+})
+
+// Avatar styling
+const avatarClass = computed(() => {
+  switch (props.state) {
+    case 'at_bat':
+      return 'bg-gradient-to-br from-amber-700 to-amber-800'
+    case 'on_base':
+      return 'bg-gradient-to-br from-green-700 to-green-800 ring-2 ring-green-500/50'
+    default:
+      return 'bg-gradient-to-br from-gray-600 to-gray-700'
+  }
+})
+
+// Subtext styling
+const subtextClass = computed(() => {
+  switch (props.state) {
+    case 'at_bat':
+      return 'text-amber-400'
+    case 'on_base':
+      return 'text-green-400'
+    default:
+      return 'text-gray-400'
+  }
+})
+
+// Status text (AT BAT, On 1st, etc.)
+const statusText = computed(() => {
+  if (props.state === 'at_bat') {
+    return 'AT BAT'
+  }
+  if (props.basePosition) {
+    return `On ${props.basePosition}`
+  }
+  return null
+})
+</script>
diff --git a/frontend-sba/components/Lineup/PositionSelector.vue b/frontend-sba/components/Lineup/PositionSelector.vue
new file mode 100644
index 0000000..d97f17b
--- /dev/null
+++ b/frontend-sba/components/Lineup/PositionSelector.vue
@@ -0,0 +1,93 @@
+<template>
+  <div class="position-selector">
+    <div class="text-xs text-gray-400 mb-2">
+      {{ label }}
+      <span v-if="required" class="text-red-400">(required)</span>
+    </div>
+    <div class="flex flex-wrap gap-1.5">
+      <button
+        v-for="pos in displayPositions"
+        :key="pos"
+        :class="[
+          'px-3 py-2 text-xs font-bold rounded-lg transition-colors select-none touch-manipulation',
+          getPositionClass(pos)
+        ]"
+        :disabled="isDisabled(pos)"
+        @click="selectPosition(pos)"
+      >
+        {{ pos }}
+      </button>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { computed } from 'vue'
+
+type SubstitutionMode = 'pinch_hitter' | 'pinch_runner' | 'defensive_replacement' | 'relief_pitcher' | 'position_change'
+
+interface Props {
+  mode: SubstitutionMode
+  modelValue: string | null
+  currentPosition?: string | null
+  label?: string
+  required?: boolean
+}
+
+const props = withDefaults(defineProps<Props>(), {
+  currentPosition: null,
+  label: 'Position for new player:',
+  required: false,
+})
+
+const emit = defineEmits<{
+  'update:modelValue': [value: string]
+}>()
+
+// Standard field positions
+const FIELD_POSITIONS = ['C', '1B', '2B', '3B', 'SS', 'LF', 'CF', 'RF'] as const
+
+// Compute display positions based on mode
+const displayPositions = computed(() => {
+  switch (props.mode) {
+    case 'pinch_hitter':
+      return ['PH', ...FIELD_POSITIONS]
+    case 'pinch_runner':
+      return ['PR', ...FIELD_POSITIONS]
+    case 'defensive_replacement':
+    case 'position_change':
+      return FIELD_POSITIONS
+    case 'relief_pitcher':
+      return ['P']
+    default:
+      return FIELD_POSITIONS
+  }
+})
+
+// Check if a position should be disabled
+const isDisabled = (pos: string): boolean => {
+  // For position change, disable the current position
+  if (props.mode === 'position_change' && pos === props.currentPosition) {
+    return true
+  }
+  return false
+}
+
+// Get CSS class for position button
+const getPositionClass = (pos: string): string => {
+  if (isDisabled(pos)) {
+    return 'bg-gray-600 text-gray-400 cursor-not-allowed'
+  }
+  if (props.modelValue === pos) {
+    return 'bg-blue-600 text-white'
+  }
+  return 'bg-gray-700 text-gray-300 hover:bg-gray-600'
+}
+
+// Handle position selection
+const selectPosition = (pos: string) => {
+  if (!isDisabled(pos)) {
+    emit('update:modelValue', pos)
+  }
+}
+</script>
diff --git a/frontend-sba/components/Lineup/UnifiedLineupTab.vue b/frontend-sba/components/Lineup/UnifiedLineupTab.vue
new file mode 100644
index 0000000..c7e996a
--- /dev/null
+++ b/frontend-sba/components/Lineup/UnifiedLineupTab.vue
@@ -0,0 +1,426 @@
+<template>
+  <div class="unified-lineup-tab">
+    <!-- Pre-game: Show LineupBuilder -->
+    <template v-if="!isGameActive">
+      <LineupBuilder
+        :game-id="gameId"
+        :team-id="myTeamId"
+        @lineups-submitted="handleLineupSubmit"
+      />
+    </template>
+
+    <!-- Mid-game: Read-only lineup with substitution actions -->
+    <template v-else>
+      <!-- Team Tabs -->
+      <div class="flex gap-2 mb-4 bg-gray-800/50 p-1 rounded-xl inline-flex">
+        <button
+          :class="[
+            'px-4 py-2 text-sm font-semibold rounded-lg transition-colors select-none',
+            isViewingAwayTeam ? 'bg-blue-600 text-white' : 'text-gray-400 hover:bg-gray-700/50'
+          ]"
+          @click="viewingTeamId = awayTeamId"
+        >
+          {{ awayTeamName }}
+        </button>
+        <button
+          :class="[
+            'px-4 py-2 text-sm font-semibold rounded-lg transition-colors select-none',
+            !isViewingAwayTeam ? 'bg-blue-600 text-white' : 'text-gray-400 hover:bg-gray-700/50'
+          ]"
+          @click="viewingTeamId = homeTeamId"
+        >
+          {{ homeTeamName }}
+        </button>
+      </div>
+
+      <!-- Context indicator -->
+      <p class="text-xs text-gray-400 mb-4">
+        Mid-game view
+        <template v-if="isMyTeam">
+          • Your team is {{ isBatting ? 'BATTING' : 'FIELDING' }}
+        </template>
+      </p>
+
+      <!-- Batting Order Section -->
+      <div class="mb-4">
+        <h2 class="text-sm font-semibold text-gray-400 mb-2 uppercase tracking-wide">Batting Order</h2>
+
+        <LineupSlotRow
+          v-for="slot in battingOrderSlots"
+          :key="slot.lineup_id"
+          :player="slot"
+          :batting-order="slot.batting_order"
+          :state="getSlotState(slot)"
+          :is-expanded="expandedSlotId === slot.lineup_id && expandedMode !== 'position_change'"
+          :show-actions="canSubstitute(slot)"
+          :show-position-change="canChangePosition(slot)"
+          :substitute-label="getSubstituteLabel(slot)"
+          @substitute="openSubstitution(slot)"
+          @change-position="openPositionChange(slot)"
+          @cancel="closeExpanded"
+        >
+          <template #expanded>
+            <InlineSubstitutionPanel
+              :substitution-type="getSubstitutionType(slot)"
+              :bench-players="benchPlayers"
+              :current-position="slot.position"
+              :team-id="viewingTeamId"
+              :player-out-lineup-id="slot.lineup_id"
+              @submit="handleSubstitutionSubmit"
+            />
+          </template>
+        </LineupSlotRow>
+      </div>
+
+      <!-- Runners on Base Section (when batting) -->
+      <div v-if="isBatting && runnersOnBase.length > 0" class="mb-4">
+        <h2 class="text-sm font-semibold text-green-400 mb-2 uppercase tracking-wide flex items-center gap-2">
+          <span>◆</span> Runners on Base
+        </h2>
+
+        <div class="bg-green-900/20 rounded-lg border border-green-700/30 p-2.5 space-y-2">
+          <LineupSlotRow
+            v-for="runner in runnersOnBase"
+            :key="`runner-${runner.lineup_id}`"
+            :player="runner"
+            :base-position="getBasePosition(runner)"
+            :state="'on_base'"
+            :is-expanded="expandedSlotId === runner.lineup_id && expandedMode === 'pinch_runner'"
+            :show-actions="canSubstitute(runner)"
+            :show-position-change="false"
+            substitute-label="Pinch Run"
+            @substitute="openPinchRunner(runner)"
+            @cancel="closeExpanded"
+          >
+            <template #expanded>
+              <InlineSubstitutionPanel
+                substitution-type="pinch_runner"
+                :bench-players="benchPlayers"
+                :current-position="runner.position"
+                :team-id="viewingTeamId"
+                :player-out-lineup-id="runner.lineup_id"
+                @submit="handleSubstitutionSubmit"
+              />
+            </template>
+          </LineupSlotRow>
+        </div>
+      </div>
+
+      <!-- Pitcher Section -->
+      <div class="mb-4">
+        <h2 class="text-sm font-semibold text-gray-400 mb-2 uppercase tracking-wide">
+          {{ isStartingPitcher ? 'Starting Pitcher' : 'Current Pitcher' }}
+        </h2>
+
+        <LineupSlotRow
+          v-if="currentPitcherLineup"
+          :player="currentPitcherLineup"
+          :is-pitcher="true"
+          :state="expandedSlotId === currentPitcherLineup.lineup_id ? 'expanded' : 'normal'"
+          :is-expanded="expandedSlotId === currentPitcherLineup.lineup_id"
+          :show-actions="canChangePitcher"
+          :show-position-change="false"
+          substitute-label="Change Pitcher"
+          @substitute="openPitchingChange"
+          @cancel="closeExpanded"
+        >
+          <template #expanded>
+            <InlineSubstitutionPanel
+              substitution-type="relief_pitcher"
+              :bench-players="benchPlayers"
+              :current-position="'P'"
+              :team-id="viewingTeamId"
+              :player-out-lineup-id="currentPitcherLineup.lineup_id"
+              @submit="handleSubstitutionSubmit"
+            />
+          </template>
+        </LineupSlotRow>
+      </div>
+
+      <!-- Position Change Panel (separate from substitution) -->
+      <div v-if="expandedMode === 'position_change' && positionChangeSlot" class="mb-4">
+        <h2 class="text-sm font-semibold text-blue-400 mb-2 uppercase tracking-wide">Position Change</h2>
+
+        <LineupSlotRow
+          :player="positionChangeSlot"
+          :state="'position_change'"
+          :is-expanded="true"
+          :show-actions="false"
+          @cancel="closeExpanded"
+        >
+          <template #expanded>
+            <InlineSubstitutionPanel
+              substitution-type="position_change"
+              :bench-players="[]"
+              :current-position="positionChangeSlot.position"
+              :team-id="viewingTeamId"
+              :player-out-lineup-id="positionChangeSlot.lineup_id"
+              @submit="handleSubstitutionSubmit"
+            />
+          </template>
+        </LineupSlotRow>
+      </div>
+    </template>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref, computed } from 'vue'
+import { useGameStore } from '~/store/game'
+import { useGameActions } from '~/composables/useGameActions'
+import type { Lineup } from '~/types'
+import LineupBuilder from '~/components/Game/LineupBuilder.vue'
+import LineupSlotRow from './LineupSlotRow.vue'
+import InlineSubstitutionPanel from './InlineSubstitutionPanel.vue'
+
+type ExpandedMode = 'substitution' | 'position_change' | 'pinch_runner' | null
+
+interface Props {
+  gameId: string
+  myTeamId: number | null
+  homeTeamName?: string
+  awayTeamName?: string
+}
+
+const props = withDefaults(defineProps<Props>(), {
+  homeTeamName: 'Home',
+  awayTeamName: 'Away',
+})
+
+const emit = defineEmits<{
+  lineupsSubmitted: [result: unknown]
+}>()
+
+const gameStore = useGameStore()
+const { submitSubstitution, getBench } = useGameActions()
+
+// Local state
+const viewingTeamId = ref<number>(props.myTeamId ?? gameStore.gameState?.away_team_id ?? 0)
+const expandedSlotId = ref<number | null>(null)
+const expandedMode = ref<ExpandedMode>(null)
+
+// Computed - Game state
+const isGameActive = computed(() => gameStore.gameStatus === 'active')
+const homeTeamId = computed(() => gameStore.gameState?.home_team_id ?? 0)
+const awayTeamId = computed(() => gameStore.gameState?.away_team_id ?? 0)
+
+// Computed - Team viewing
+const isViewingAwayTeam = computed(() => viewingTeamId.value === awayTeamId.value)
+const isMyTeam = computed(() => viewingTeamId.value === props.myTeamId)
+const isBatting = computed(() => viewingTeamId.value === gameStore.battingTeamId)
+const isFielding = computed(() => viewingTeamId.value === gameStore.fieldingTeamId)
+
+// Computed - Lineups
+const currentTeamLineup = computed(() => {
+  return isViewingAwayTeam.value
+    ? gameStore.awayLineup
+    : gameStore.homeLineup
+})
+
+const activeLineup = computed(() => {
+  return currentTeamLineup.value.filter(p => p.is_active)
+})
+
+const benchPlayers = computed(() => {
+  return isViewingAwayTeam.value
+    ? gameStore.awayBench
+    : gameStore.homeBench
+})
+
+const battingOrderSlots = computed(() => {
+  return activeLineup.value
+    .filter(p => p.batting_order !== null && p.position !== 'P')
+    .sort((a, b) => (a.batting_order ?? 0) - (b.batting_order ?? 0))
+})
+
+// Computed - Runners on base
+const runnersOnBase = computed(() => {
+  const runners: Array<Lineup & { base: '1B' | '2B' | '3B' }> = []
+  const state = gameStore.gameState
+
+  if (!state) return runners
+
+  // Get runners from game state and find their lineup data
+  if (state.on_first) {
+    const lineup = gameStore.findPlayerInLineup(state.on_first.lineup_id)
+    if (lineup) runners.push({ ...lineup, base: '1B' })
+  }
+  if (state.on_second) {
+    const lineup = gameStore.findPlayerInLineup(state.on_second.lineup_id)
+    if (lineup) runners.push({ ...lineup, base: '2B' })
+  }
+  if (state.on_third) {
+    const lineup = gameStore.findPlayerInLineup(state.on_third.lineup_id)
+    if (lineup) runners.push({ ...lineup, base: '3B' })
+  }
+
+  return runners
+})
+
+// Computed - Pitcher
+const currentPitcherLineup = computed(() => {
+  // Get pitcher for the viewing team
+  return activeLineup.value.find(p => p.position === 'P')
+})
+
+const isStartingPitcher = computed(() => {
+  return currentPitcherLineup.value?.is_starter ?? true
+})
+
+// Note: For demo/testing, allow pitcher changes for the team being viewed
+const canChangePitcher = computed(() => {
+  return isFielding.value
+})
+
+// Computed - Current batter
+const currentBatterLineupId = computed(() => {
+  return gameStore.currentBatter?.lineup_id ?? null
+})
+
+// Computed - Position change slot
+const positionChangeSlot = computed(() => {
+  if (expandedMode.value !== 'position_change' || !expandedSlotId.value) return null
+  return activeLineup.value.find(p => p.lineup_id === expandedSlotId.value) ?? null
+})
+
+// Get slot state for display
+function getSlotState(slot: Lineup): 'normal' | 'at_bat' | 'on_base' | 'expanded' {
+  if (expandedSlotId.value === slot.lineup_id) return 'expanded'
+  if (isBatting.value && slot.lineup_id === currentBatterLineupId.value) return 'at_bat'
+  if (runnersOnBase.value.some(r => r.lineup_id === slot.lineup_id)) return 'on_base'
+  return 'normal'
+}
+
+// Get base position for a runner
+function getBasePosition(runner: Lineup & { base?: '1B' | '2B' | '3B' }): '1B' | '2B' | '3B' | null {
+  return runner.base ?? null
+}
+
+// Can substitute at this slot?
+// Note: For demo/testing, allow subs for whichever team is being viewed
+// In production, could restrict to only your managed team
+function canSubstitute(slot: Lineup): boolean {
+  if (!slot.is_active) return false
+  return true
+}
+
+// Can change position at this slot?
+// Note: For demo/testing, allow position changes for the team being viewed
+function canChangePosition(slot: Lineup): boolean {
+  if (!slot.is_active) return false
+  // Can change position when that team is fielding
+  return isFielding.value
+}
+
+// Get substitute button label
+function getSubstituteLabel(slot: Lineup): string {
+  if (isBatting.value && slot.lineup_id === currentBatterLineupId.value) {
+    return 'Pinch Hit'
+  }
+  return 'Substitute'
+}
+
+// Get substitution type for a slot
+function getSubstitutionType(slot: Lineup): 'pinch_hitter' | 'pinch_runner' | 'defensive_replacement' | 'relief_pitcher' {
+  if (slot.position === 'P') return 'relief_pitcher'
+  if (isBatting.value && slot.lineup_id === currentBatterLineupId.value) return 'pinch_hitter'
+  if (runnersOnBase.value.some(r => r.lineup_id === slot.lineup_id)) return 'pinch_runner'
+  return 'defensive_replacement'
+}
+
+// Open substitution panel for a slot
+function openSubstitution(slot: Lineup) {
+  expandedSlotId.value = slot.lineup_id
+  expandedMode.value = 'substitution'
+  // Fetch bench players when opening substitution panel
+  getBench(viewingTeamId.value)
+}
+
+// Open pinch runner panel
+function openPinchRunner(runner: Lineup) {
+  expandedSlotId.value = runner.lineup_id
+  expandedMode.value = 'pinch_runner'
+  // Fetch bench players when opening substitution panel
+  getBench(viewingTeamId.value)
+}
+
+// Open position change panel
+function openPositionChange(slot: Lineup) {
+  expandedSlotId.value = slot.lineup_id
+  expandedMode.value = 'position_change'
+}
+
+// Open pitching change panel
+function openPitchingChange() {
+  if (currentPitcherLineup.value) {
+    expandedSlotId.value = currentPitcherLineup.value.lineup_id
+    expandedMode.value = 'substitution'
+    // Fetch bench players when opening substitution panel
+    getBench(viewingTeamId.value)
+  }
+}
+
+// Close expanded panel
+function closeExpanded() {
+  expandedSlotId.value = null
+  expandedMode.value = null
+}
+
+// Handle substitution submit
+async function handleSubstitutionSubmit(payload: {
+  playerOutLineupId: number
+  playerInCardId?: number
+  newPosition: string
+  teamId: number
+  type: string
+}) {
+  try {
+    // Map our type to backend substitution type
+    let backendType: 'pinch_hitter' | 'defensive_replacement' | 'pitching_change'
+
+    switch (payload.type) {
+      case 'pinch_hitter':
+      case 'pinch_runner':
+        backendType = 'pinch_hitter' // Backend treats PR as PH for now
+        break
+      case 'relief_pitcher':
+        backendType = 'pitching_change'
+        break
+      case 'position_change':
+        // TODO: Position change endpoint
+        console.log('Position change not yet implemented:', payload)
+        closeExpanded()
+        return
+      default:
+        backendType = 'defensive_replacement'
+    }
+
+    if (payload.playerInCardId) {
+      await submitSubstitution({
+        game_id: props.gameId,
+        type: backendType,
+        player_out_lineup_id: payload.playerOutLineupId,
+        player_in_card_id: payload.playerInCardId,
+        team_id: payload.teamId,
+        new_position: payload.newPosition,
+      })
+    }
+
+    closeExpanded()
+  } catch (error) {
+    console.error('Substitution failed:', error)
+    // TODO: Show error toast
+  }
+}
+
+// Handle lineup submit from LineupBuilder
+function handleLineupSubmit(result: unknown) {
+  emit('lineupsSubmitted', result)
+}
+</script>
+
+<style scoped>
+.unified-lineup-tab {
+  @apply w-full;
+}
+</style>
diff --git a/frontend-sba/store/game.ts b/frontend-sba/store/game.ts
index 4003106..e1add09 100644
--- a/frontend-sba/store/game.ts
+++ b/frontend-sba/store/game.ts
@@ -15,6 +15,7 @@ import type {
   OffensiveDecision,
   RollData,
   Lineup,
+  BenchPlayer,
 } from '~/types'
 
 export const useGameStore = defineStore('game', () => {
@@ -25,6 +26,8 @@ export const useGameStore = defineStore('game', () => {
   const gameState = ref<GameState | null>(null)
   const homeLineup = ref<Lineup[]>([])
   const awayLineup = ref<Lineup[]>([])
+  const homeBench = ref<BenchPlayer[]>([])
+  const awayBench = ref<BenchPlayer[]>([])
   const playHistory = ref<PlayResult[]>([])
   const currentDecisionPrompt = ref<DecisionPrompt | null>(null)
   const pendingRoll = ref<RollData | null>(null)
@@ -186,6 +189,19 @@ export const useGameStore = defineStore('game', () => {
     }
   }
 
+  /**
+   * Set bench players for a specific team
+   * Bench players come from RosterLink (players not in active lineup)
+   * with is_pitcher/is_batter computed properties for UI filtering
+   */
+  function setBench(teamId: number, bench: BenchPlayer[]) {
+    if (teamId === gameState.value?.home_team_id) {
+      homeBench.value = bench
+    } else if (teamId === gameState.value?.away_team_id) {
+      awayBench.value = bench
+    }
+  }
+
   /**
    * Set play history (replaces entire array - used for initial sync)
    * O(1) operation - no deduplication needed
@@ -323,6 +339,8 @@ export const useGameStore = defineStore('game', () => {
     gameState.value = null
     homeLineup.value = []
     awayLineup.value = []
+    homeBench.value = []
+    awayBench.value = []
     playHistory.value = []
     currentDecisionPrompt.value = null
     pendingRoll.value = null
@@ -373,6 +391,8 @@ export const useGameStore = defineStore('game', () => {
     gameState: readonly(gameState),
     homeLineup: readonly(homeLineup),
     awayLineup: readonly(awayLineup),
+    homeBench: readonly(homeBench),
+    awayBench: readonly(awayBench),
     playHistory: readonly(playHistory),
     currentDecisionPrompt: readonly(currentDecisionPrompt),
     pendingRoll: readonly(pendingRoll),
@@ -421,6 +441,7 @@ export const useGameStore = defineStore('game', () => {
     updateGameState,
     setLineups,
     updateLineup,
+    setBench,
     setPlayHistory,
     addPlayToHistory,
     setDecisionPrompt,
diff --git a/frontend-sba/types/index.ts b/frontend-sba/types/index.ts
index 3ecb6ec..43b61a2 100644
--- a/frontend-sba/types/index.ts
+++ b/frontend-sba/types/index.ts
@@ -37,6 +37,7 @@ export type {
   SbaPlayer,
   Lineup,
   TeamLineup,
+  BenchPlayer,
   LineupDataResponse,
   SubstitutionType,
   SubstitutionRequest,
diff --git a/frontend-sba/types/player.ts b/frontend-sba/types/player.ts
index 43a04c0..680c48c 100644
--- a/frontend-sba/types/player.ts
+++ b/frontend-sba/types/player.ts
@@ -83,6 +83,33 @@ export interface TeamLineup {
   players: Lineup[]
 }
 
+/**
+ * Bench player from RosterLink (for substitutions)
+ * Backend: SbaRosterLinkData with computed is_pitcher/is_batter
+ *
+ * This is distinct from Lineup - it represents roster players
+ * not currently in the active lineup.
+ */
+export interface BenchPlayer {
+  roster_id: number
+  player_id: number
+  player_positions: string[]  // Natural positions (e.g., ["SS", "2B"])
+  is_pitcher: boolean         // True if player has pitching positions
+  is_batter: boolean          // True if player has batting positions
+
+  // Player data (from SBA API)
+  player: {
+    id: number
+    name: string
+    image: string
+    headshot: string
+    // Legacy position fields for backwards compatibility
+    pos_1: string | null
+    pos_2: string | null
+    pos_3: string | null
+  }
+}
+
 /**
  * Lineup data response from server
  */