There are two Substitution screens, one for each team, used to make mid-game substitutions. These screens are almost identical to the Team Lineups and Starting Pitcher screens seen during pre-game.

The Substitution screen has a game-in-progress box score in the lower right corner.

Substituting on Offense (Pinch Hitting)

To insert a pinch hitter while you are the offensive team, drag a new hitter from the roster list on the top of the screen directly on top of the player you wish to replace in the lineup. Players in red have already been used in the game, and cannot be inserted as pinch hitters. The number of the player currently at bat is highlighted. Once you drag a player into the lineup, his position will be listed as 'PH' (pinch hitter). You can choose a position for this player now by using the drop-down. If you do not choose a position, you will be prompted to choose a position for the player at the end of the half-inning.

Substituting on Defense

Defensive substitutions are handled similarly, by dragging players from the roster list into the batting lineup. You can also change the positions of players already on the field by changing player positions in the drop-downs next to each player.

Warming up Pitchers

If you have chosen to use the pitcher warmup rule described in the Pre-Game Options, then pitchers must be warmed up before being inserted in the game or their performance may suffer drastically. A pitcher typically needs 12-15 pitches to get warm. To warm up a pitcher, drag them to the bullpen box on the right side of the screen.

Subtituting on Defense (Pitchers)

The Pitcher Status box in the lower right shows the current pitcher as well as any pitchers warming up in the bullpen. To substitute a pitcher, simply drag a pitcher over the pitcher listed in the current pitcher box.

Performing a 'Double-Switch'

A double-switch is a type of player substitution typically used only in leagues with no designated hitter rule. The double-switch is used to avoid having a new pitcher bat soon after entering the game. In a double-switch, a pitcher replaces a player who will not bat soon, and a defensive player replaces the former pitcher. This allows you to bring in a new pitcher without having him bat soon.

To execute a double-switch in OOTP when you are batting, use the following steps:

1. During your at-bat, insert a pinch hitter for pitcher, making sure that his position is PH.
2. Return to the game, and play out the rest of your at-bat.
3. When you take the field, OOTP will tell you that you need a new pitcher.
4. Change the pinch hitter's position to his new fielding role, or drag a new fielder to replace the pinch hitter and give him a position.
5. Drag a new pitcher into the spot of the ex-fielder that's being replaced and change his position from '-' to 'P.'

To execute a double-switch in OOTP when you are in the field, use the following steps:

1. While you are in the field, set the position of the defensive player you are replacing to '-'.
2. Set the position of the pitcher you are replacing to '-'.
3. Drag your new pitcher over the defensive player you are replacing.
4. Drag your new defensive player over the pitcher you are replacing.
5. Set the pitcher's position to 'P.'
6. Set the new defensive player's position.
7. Return to the game.

Note: There are other ways you can construct a double-switch. However, sometimes using different steps can cause the switch to be recorded strangely on the box score, for example showing that your pitcher played center field. Using these steps ensures that your box score will be as 'true' as possible.