If a coach sends out a courtesy runner for F2 and F2 later tries to re-enter, what is the ruling?

In baseball, the concept of a courtesy runner is specifically outlined to accommodate situations involving players such as the catcher (F2) who may need a breather or assistance in running the bases due to circumstances like injury or fatigue. When a courtesy runner is used for F2, the key rule pertaining to re-entry comes into play.

F2 can only return to run for themselves if certain conditions are met. The rule stipulates that once a courtesy runner has taken the field, the player they are running for (F2) is generally not permitted to re-enter until the offensive team bats around. This means that F2 must wait until every player in the batting order has had a turn at bat before they can return to the game.

This ruling preserves the integrity of the game by preventing a player from indefinitely cycling into and out of play in a way that could disrupt the flow of the game or undermine the rules surrounding player substitutions. Consequently, F2's opportunity to re-enter is contingent upon that continuity established by the team batting around rather than being a straightforward return to the game at any valid moment.