In the second period of the game between Canada and Sweden. Minnesota Wild prospect Mathew Dumba hit Carolina Hurricanes prospect Erik Karlsson. Dumba was given a major and a game misconduct for kneeing.
Dumba could face supplementary discipline. If he's suspended, it's going to be a tricky situation for Team Canada. They might start the tournament, which is starting on December 26th, with 5 defensemen. That really seems to be an unlikely scenario to happen though. They've until Christmas to officially finalize their roster.
For the record, Alexander Edler was suspended 2 games during the 2013 IIHF World Championship for a knee hit on Eric Staal. The IIHF then added 2 additional games to Edler, but it doesn't matter in this case.
If Dumba is suspended, it's fair to think that he'd probably get 1 or 2 games. It's definitely not something we like to see, but we'll find out later.