Substitution rules: five subs and concussion subs

The detail worth getting right is that “five subs” is a competition’s choice under the Laws of the Game, not a single global number, and that the newer concussion substitute rule works differently from an ordinary substitution in ways that catch people out. Here is exactly how the allowance, the windows and the concussion protocol work, under IFAB’s Law 3.

How many substitutes are actually allowed

The Laws of the Game set five as a ceiling, not a mandate. Law 3 states that 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.” A lower-level league, a domestic cup or a grassroots competition can run three substitutes instead, and plenty do.

The five-substitute figure now standard at the Premier League, the Champions League and the rest of Europe’s major leagues is a rule those competitions chose to adopt, after IFAB first allowed it as a temporary measure during the pandemic and later made it a permanent option for top-level competitions to select.

The substitution window rule

Being allowed five substitutes does not mean a manager can stop the game five separate times to make them. Competitions that permit five subs also cap the changes at three substitution opportunities during play. A substitution opportunity is one stoppage used to make a change, and Law 3 confirms that swapping more than one player during the same stoppage still only counts as one opportunity, so a triple change made together uses up just one of the three.

On top of those three, there is a separate opportunity at half time that does not count against the limit. In practice, a team can make changes at up to four separate moments across a normal 90 minutes: three windows during play, plus the interval. Extra time adds further scope. Any substitutes or substitution opportunities a team has not used in normal time carry over into extra time, and where a competition allows one additional substitute for extra time, each team also gets one additional substitution opportunity to use it. The break between full time and extra time, and half time within extra time itself, both allow further changes without touching the opportunity count, the same way normal half time does.

Who can be substituted, and whether they can come back

Any outfield player or the goalkeeper can be substituted at any point, as long as the team still has an unused substitution opportunity and an unused substitute available. Once a player is withdrawn, the law is direct about what happens next: they go to the technical area or the dressing room and take no further part in the match. There is no rule letting a normally substituted player return during that same match.

The one exception is deliberately narrow. IFAB permits return substitutions, where a withdrawn player can come back on later in the same match, but only in youth, veterans, disability and grassroots football, and only where the relevant national association, confederation or FIFA has agreed to it for that competition. Senior professional football does not use return substitutions.

The concussion substitute rule

This is the newest and least understood part of the substitution rules, so it is worth stating precisely how it differs from an ordinary change.

It is additional, not drawn from the normal pool. Each team gets a maximum of one concussion substitute per match, on top of whatever normal substitute limit the competition runs, three or five. It does not use up one of the team’s normal substitutes or substitution opportunities.

The player coming off cannot return, at all, including in a penalty shootout, under IFAB’s concussion substitution protocol.

The opposing team gets a matching option. When a team makes a concussion substitution, the opposing team is offered its own additional substitute and additional substitution opportunity. That additional substitute can only be used for this purpose, not folded into a normal change elsewhere in the match.

One detail worth flagging for squads with a small bench: where a competition names exactly as many substitutes as its normal limit allows, the concussion substitute can be a player who has already been substituted earlier in the same match. That is the one case where a withdrawn player effectively re-enters the matchday picture, through the concussion protocol rather than the normal substitution rule.

Why the timing of a substitution matters for props

None of this is just procedure. A player coming off ends their contribution to any prop market tied to their own output, shots, shots on target, cards, fouls, tackles, for the rest of that game, unless a specific bookmaker offer intervenes. Because a normal substitution is permanent under the law, the moment a manager makes the change is the moment that player’s stat line for the match is finished.

That is exactly the situation several bookmakers built a promotional mechanic around, rolling a prop bet from the departing player onto the substitute who replaces them, at the same stake and odds, instead of letting it settle early as a loss. FootyMetrics has a separate page on the super sub offer and its many names, covering how each bookmaker brands that mechanic, which markets and competitions it covers, and the edge cases like red cards and extra time. This page is about the underlying law. That one is about what bookmakers do with it.