Substitution rules, explained: five subs, three windows and concussion subs

For most of football’s history teams could make three substitutions a match. That changed around 2020, when the Laws were updated to allow up to five, a shift first brought in to help players through congested, pandemic-era schedules and then kept. Exactly how many are allowed can still vary by competition, but five is now standard in most top leagues.

To stop teams from using substitutions to waste time, the five changes must be made within three stoppages in play (plus half-time, which does not count as a window). So a team can bring on all five, but only across three separate moments — a manager who spreads changes across four stoppages will be refused the fourth.

Football has added concussion substitutions on top of the normal allowance. If a player is suspected of having a head injury, the team can replace them with an additional, permanent substitution that does not count toward their normal total — and the opponent gets an extra one too, to keep it fair. Player safety is put above tactical cost.

In almost all of football, a substituted player cannot return — substitutions are permanent, unlike the rolling substitutions of some other sports. There are limited exceptions in grassroots and friendly matches, but in the professional game, once you are replaced, your match is over.