Law 3 The Number of Players - Infringements and Sanctions.
If a substitute or substituted player enters the field of play without the referee's permission:
* The referee stops play (although not immediately if the substitute or substituted player does not interfere with
play)
* The referee cautions him for unsporting behaviour and orders him to leave the field of play.
* If the referee has stopped play, it is restarted with an indirect free kick for the opposing team from the position of the ball at the time of the stoppage (see Law 13 - Position of free kick)
If a named substitute enters the field of play instead of a named player at the start of the match and the referee is not informed of this change:
* The referee allows the named substitute to continue the match.
* No disciplinary sanction is taken against the named substitute.
* The number of substitutions allowed by the offending team is not reduced.
* The referee reports the incident to the appropriate authorities.
If a player changes places with the goalkeeper without the referee's permission before the change is
made:
* The referee allows play to continue.
* The referee cautions the players concerned when the ball is next out of play.
In the event of any other infringements of this Law:
* The players concerned are cautioned
* The match is restarted with an indirect free kick, to be taken by a player of the opposing team from the position of the ball at the time of the stoppage (see Law 13 - Position of free kick.
* The referee stops play (although not immediately if the substitute or substituted player does not interfere with
play)
* The referee cautions him for unsporting behaviour and orders him to leave the field of play.
* If the referee has stopped play, it is restarted with an indirect free kick for the opposing team from the position of the ball at the time of the stoppage (see Law 13 - Position of free kick)
If a named substitute enters the field of play instead of a named player at the start of the match and the referee is not informed of this change:
* The referee allows the named substitute to continue the match.
* No disciplinary sanction is taken against the named substitute.
* The number of substitutions allowed by the offending team is not reduced.
* The referee reports the incident to the appropriate authorities.
If a player changes places with the goalkeeper without the referee's permission before the change is
made:
* The referee allows play to continue.
* The referee cautions the players concerned when the ball is next out of play.
In the event of any other infringements of this Law:
* The players concerned are cautioned
* The match is restarted with an indirect free kick, to be taken by a player of the opposing team from the position of the ball at the time of the stoppage (see Law 13 - Position of free kick.