An injury (usually very minor) that a star or important player sustains right before or during a big game. This usually occurs when the player knows that they have no chance of winning and decides to save face. This allows these players to say things like "We would have won if I played" or "We only lost because I was injured" further protecting their reputation.
Joe: Did you hear, Lebron cant play in game four of the NBA Championships, he injured his big toe.
RJ: Haha, thats such a Choke Injury, he knows that the Lakers are just going to win tonight and end the series in a sweep.