World Junior Championship: Will Mat Dumba face a suspension for his knee on Erik Karlsson?

Canadian pre-Christmas traditions include trimming the tree, wrapping gifts, and hoping that members of Team Canada don't get suspended during the pre-tournament games.

Team Canada is playing three pre-tournament games before the start of the IIHF U-20 World Championships, and escaped their first against Finland scot-free, with the only questionable hit a boarding call on forward Kerby Rychel. The team got into some potential trouble against Sweden on Sunday. Defenceman Mathew Dumba, on loan from the Minnesota Wild and expected to be one of the team's anchors on defence, hit Swedish forward and Carolina Hurricanes prospect Erik Karlsson with a knee-on-knee hit.

Here's a video of the collision:

Dumba earned five-and-a-game on the play, reducing Canada to six defencemen for the remainder of the game. These pre-tournament games are not sanctioned by the IIHF but they can review for discipline. Last year, Canadian forward Boone Jenner was given a three-game suspension for boarding Sweden's Jesper Petterssen in the pre-tournament competition.

Team Canada still has one forward cut to make, which will likely come later on Sunday, but after sending Damon Severson home Sunday, their seven defencemen are set. Should Dumba be suspended, you have to wonder if Canada may make an emergency roster change. Though defenceman Griffin Reinhart of the Edmonton Oil Kings has been playing the exhibition contests, he still has three IIHF games to serve thanks to an incident which occurred last year in the semifinal contest.

Should Dumba be disciplined further, there's a chance Canada could open the tournament against Germany with just five defencemen with Dumba and Reinhart sitting up in the pressbox. Teams are allowed to dress a 22-man roster in IIHF play and traditionally, Canada has gone with 13 forwards and 7 defencemen.

The team will be able to handle going down to six defencemen until the New Year's Eve contest against the United States when Reinhart will be eligible to return. Canada doesn't have to submit its roster until December 25, so if Dumba is out for a serious amount of games, will Canada attempt to replace Reinhart or Dumba on the roster with a player eligible to play in the early tournament contests?

As for the collision itself, the five-and-a-game would probably be sufficient based on a strict interpretation of the North American standard of discipline. The hit probably looked a little worse than it actually was, since Dumba makes contact with the leg that in the air, giving the illusion that the knee is buckling. Karlsson was hurt on the play and didn't return, but that could just be precautionary seeing as these games mean little.

It's possible Dumba gets just one game, to be served for the final pre-tournament contest tomorrow against Switzerland, or no games at all. However, with three suspended players at last year's tournament, and the potential to have another sit out games before the tournament even begins, it's no longer fair to call the IIHF's disciplinary standards into question. There appears to be a gap between what is acceptable and what Team Canada players believe is acceptable in international hockey, and Dumba is just the latest player with a controversial hit at this tournament.