No word yet on how serious of an illness Makar is dealing with, but it’s certainly worrisome for the Canadians, as the team is already without Shea Theodore, who left Wednesday’s game against Sweden with a wrist injury, and is now considered week-to-week.

Makar played a whopping 28:06 in Canada’s overtime win over the Swedes, and finished the night with two shots on goal, three blocked shots, and two takeaways. Canada faces off against USA on Saturday, in what’s setting up to be a very entertaining clash of the titans.

Entering the 4 Nations Face-Off tournament, Makar had appeared in 57 games for the Avalanche, recording 22 goals, and 63 points in 57 games. The 26-year-old defenseman is averaging 25:48 of ice-time per game for Colorado, and is certainly used to playing big minutes, in high-pressured situations.

With Theodore already out of the lineup, and now with Makar unavailable to practice, Canada is permitted to have Dallas Stars‘ defenseman Thomas Harley join the team in Montreal. Despite the team’s request once Theodore went down, Harley wasn’t permitted to be with the team in Montreal, as per tournament rules.

Meanwhile, Philadelphia Flyers defenseman Travis Sanheim, who was a healthy scratch against the Swedes, will draw in for the huge matchup against the Americans. The 28-year-old Sanheim has tallied six goals, and 27 points in 57 games so far this year for the Flyers. He was paired with Drew Doughty at Canada’s practice on Friday.

Canada and USA hit the ice Saturday night from the Bell Centre in Montreal. A best-on-best matchup almost a decade in the making.