Question:
A substitute who is warming up behind his own net when his team is in danger of receiving a goal, enters the playing field and prevents the goal with his foot. What should the referee call?
And what should the referee call if he blocked the ball with his hand intentionally?
USSF answer (August 31, 2010):
According to Law 12, a player, substitute, or substituted player is sent off if he commits any of seven offenses, including denying the opposing team a goal or an obvious goal-scoring opportunity by deliberately handling the ball (this does not apply to a goalkeeper within his own penalty area) and denying an obvious goal-scoring opportunity to an opponent moving towards the player’s goal by an offense punishable by a free kick or a penalty kick.
And the Advice to Referees tells us:
12.29 SENDING-OFF OFFENSES
“A player (or substitute) who commits serious foul play, violent conduct, a deliberate handling of the ball which denies a goal or an obvious goal-scoring opportunity, or a foul which denies an obvious goal-scoring opportunity must be sent from the field.
This information is based on the IFAB Questions and Answers (published by FIFA for the IFAB) of 2006, which have not been changed.
Q&A 2006, Law 3:
13. A substitute, warming up behind his own goal, enters the field of play and prevents the ball entering the goal with his foot. What action does the referee take?
The referee stops play, cautions the substitute for unsporting behavior and the match is restarted with an indirect free kick to the opposing team where the ball was when play was stopped *.
13.1. If the player prevents the goal with his hand, what action does the referee take?
The referee stops play and sends-off the substitute for denying the opposing team a goal by deliberately handling the ball and the match is restarted with an indirect free kick to the opposing team where the ball was when play was stopped *.
Note: These restarts should be conducted in accordance with the guidance in Law 13 on the location of free kicks.
As to the substitute in Q&A 13, we believe he could also be sent off, based on the following: (a) cautioning him for unsporting behavior (the illegal entry) and then (b) cautioning him a second time for USB (an action which shows a lack of respect for the game, viz., the interference with the goal). If the substitute performs any sort of action directed at the attacker and, in the process, interferes with the goal-scoring opportunity,the referee could send him off directly if that action was violent in any way, or caution (the second one) for USB, again for showing a lack of respect. .
And, for the future, the referee should privately resolve NEVER to let subs warm up behind the net. The Laws of the Game specify the location of substitutes (the technical area) for a reason and longstanding tradition limits even their warm-up activities to an area well back from the SIDELINE.