A linesman is able to flag for a penalty, however it is at the digression of the referee to give the final decision. A penalty kick is a form of direct free kick and is awarded against a team that commits a foul inside of their penalty area. At the end of a half or extra time, additional minutes are allowed for a penalty to be taken. This must be taken from the penalty spot which is twelve yards from the goal line. The referee must make sure that all players are behind the ball on the outside of the box and if a player encroaches inside the box the penalty should be retaken. If players persist to enter the box before the ball has been kicked, they will be penalised. The player taking the kick must be identified and the goalkeeper must remain on his line until the ball has been kicked.
In a football match if a player is running towards the ball inside of the penalty area and just as they knock it around the goalkeeper there legs are taken causing them to fall over, this would be classed as a penalty. The referee would not hesitate to blow his whistle and may even issue a card to the goalkeeper, depending on whether it was purposeful or accidental. Any player from the team can then be selected to take the penalty kick and the rest of the players must be behind the ball.