After A2 takes a penalty kick and it rebounds off the goalpost back to A2, what should the referee do?

The correct action for the referee when A2 takes a penalty kick and the ball rebounds off the goalpost back to A2 is to allow play to continue, but with the understanding that a penalty kick is only valid if the ball goes into the goal or is touched by a player other than the kicker before it can be played again.

When a penalty kick is taken, the rules state that if the ball hits the goalpost, the ground, or is saved by the goalkeeper, the kicker cannot legally play the ball again until it is touched by another player. Therefore, if A2 were to play the ball again after the rebound, this would constitute a violation of the rules, leading to the need to restart with an indirect kick for the opposing team. Essentially, an indirect kick is awarded to the opposing team in situations where a player has violated the rules, such as touching the ball after taking the penalty kick without it having touched another player.

In this case, since A2 attempted to play the ball after the kick and it rebounded off the goalpost, the referee recognizes this as a situation where the procedures surrounding penalty kicks must be enforced properly, resulting in an indirect free kick for the opposing team.