The injury occurred in the first period of Canada's quarterfinal matchup against Team Sweden, when Vancouver Canucks defenseman Alexander Edler connected on a knee-on-knee. Staal immediately fell to the ice and was clearly in a great deal of pain.
He required the aide of a trainer and was unable to get off the ice under his own power.
Edler was given five minutes for kneeing, as well as a game misconduct. He will likely receive discipline from the IIHF for the action.
However, the more serious question is about Staal's health. To say he was in agony wouldn't do it justice. It certainly appeared based upon his reaction that he suffered a serious knee injury. What kind of implications this has on his 2013-14 season with the Hurricanes remains to be seen.