Soccer Rules - The Number of Players
A match is played by two teams, each consisting of not more than eleven players, one of whom is the goalkeeper. A match may not start if either team consists of fewer than seven players.
Up to a maximum of three substitutes may be used in any match played in an officialcompetition organised under the auspices of FIFA, the confederations or the nationalassociations.The rules of the competition must state how many substitutes may be nominated, fromthree up to a maximum of seven.
In other matches, substitutes may be used, provided that:
The teams concerned reach agreement on a maximum number
The referee is informed before the match
If the referee is not informed, or if no
Agreement is reached before the start of the match, no more than three substitutes are allowed.
In all matches the names of the substitutes must be given to the referee prior to the start of the match. Substitutes not so named may not take part in the match.
To replace a player by a substitute, the following conditions must be observed:
The referee is informed before any proposed substitution is made
A substitute only enters the field of play after the player being replaced has left and after receiving a signal from the referee
A substitute only enters the field of play at the halfway line and during a stoppage in the match
A substitution is completed when a substitute enters the field of play
From that moment, the substitute becomes a player and the player he has replaced ceases to be a player
A player who has been replaced takes no further part in the match
All substitutes are subject to the authority and jurisdiction of the referee, whether called upon to play or not
Changing the Goalkeeper
Any of the other players may change places with the goalkeeper, provided that:
The referee is informed before the change is made
The change is made during a stoppage in the match