hockey injuries
The injury itself would be an indication of when it happened chronologically in the game. As another poster mentioned, when the ice gets choppy towards the end of a period, a player can get his skate caught in a rut, leading to a leg injury. Concussions can happen at any time. It's just a case of the player being at the wrong place at the wrong time when he gets hit, or had his head down (see Lindros, Eric). That being said, you would probably be slightly less inclined to have this happen at the very beginning of a game. Very few serious injuries occur as a result of fighting, so the bad temper factor isn't that pronounced. Hope this helps.
Hey, thought-leadership, who is your brother in law?