Injuries are a fact of life in sport, but how they are handled by match officials can play a big part in how the participants feel about the referee's overall performance in that game. Even if there was no foul involved, managing injuries is an important skill.
Stop Play - sounds simple enough, but often does not happen quickly enough. Although players will often put the ball out of play when an injury occurs, as a courtesy to the hurt player, sometimes this is not that easy to do especially in indoor, as the ball has to clear the boards. The referee has the power to stop play at any time for an injury, which, in his/her opinion is serious. What is considered serious will often depend on the particular game - in a youth game, a ball in the face or kick on the knee that causes a player distress should be considered serious enough to stop play if the player stays down.
Assess the injury - head or neck injuries require immediate attention, and the team staff should be called onto the field without delay. Other injuries may only require help getting off the field, but if it was serious enough to stop play, then that help should be allowed.
Stay attentive to the field - once the team is looking after the injured player, the referee should remember their responsibility to maintain control over other things on the field. Players may be upset, thinking there should have been a foul or penalty.The referee should take up a position to be close enough to the injury to supervise the handling of the injury, but also where they can keep an eye on the rest of the field for potential problems. Five to ten yards is often an appropriate distance keeping the majority of players in your view.
Choose your words carefully - injuries are often "intense" moments in the game, and the official may have cause to offer words of consolation, reassurance, instruction, advice, or calming words to those who are upset. Think before you speak, and then do so in a calm, professional manner.
If there is blood - ensure that safe practice is observed. The player MUST leave the field of play. Blood on wounds must be cleaned and covered before the player is allowed to return to the field, and clothing with blood has to be replaced, even if the blood is dry. If any blood gets on the playing surface, it should be cleaned up before the game restarts.
Remember - at an injury, many eyes will be on the referee, watching how you handle the stoppage.