In addition to the 11 players on the field, teams often have a squad of reserve players, commonly referred to as substitutes. The number of substitute players can vary, but it's common to have up to 7 substitutes in professional football matches.

According to the Laws of the Game, "the number of substitutes, up to a maximum of five, which may be used in any match played in an official competition will be determined by FIFA, the confederation or the national football association." Also: In national A team matches, up to a maximum of six substitutes may be used.