Canada, along with Russia, are favorites ahead of the upcoming JVM in Edmonton.
Now, however, the host nation has suffered a heavy loss.
Captain and fixed star Kirby Dach looks to miss the entire tournament after injuring his right arm in a training match, reports Canadian TSN.
It was in the third period that Dach put a tackle on a Russian player in the middle zone.
The collision did not look particularly serious, but Dach quickly took off his glove and grabbed his right arm in pain as he headed for the locker room.
The 19-year-old was seen as one of the big stars before the JVM and has had a great rookie season in the NHL with eight goals and 15 assists in 64 games for the Chicago Blackhawks.
Canada will face Germany in the JVM premiere on Monday night.