Substitution (sport)

In team sports, substitution (or interchange) is replacing one player with another during a match. Substitute players that are not in the starting lineup (also known as bench players, backups, interchange, or reserves) reside on the bench and are available to substitute for a starter. Later in the match, that substitute may be substituted for by another substitute or by a starter who is currently on the bench.

Free substitution or rolling substitution is a rule in some sports that allows players to enter and leave the game for other players many times during the course of a game, generally during a time-out or other break in live play; and for coaches to bring in and take out players an unlimited number of times. In other sports, limited substitution restricts the manner in which players can be replaced.