MONTREAL -- Canada defenseman Shea Theodore is out for the rest of the 4 Nations Face-Off because of injury, coach Jon Cooper said after his team beat Sweden 4-3 in overtime in the first game of the NHL-run tournament, calling it a big blow.

Theodore injured his right wrist or forearm when he got crunched into the glass on a hit by Sweden's Adrian Kempe in the second period Wednesday night. Theodore immediately winced in pain, got medical attention on the bench and then went down the tunnel to get X-rays.

"What a kid, and he only got to play six minutes," Cooper said. "It's heartbreaking for the kid. And he was the first one there at the door high-fiving everybody when we came off. It's a tough one to swallow because you just know how much it means."

It's not clear how long Theodore, who plays for the Vegas Golden Knights in the NHL, might be out. Cooper would not reveal the injury.

"I guess in hindsight he got to touch the ice and get some time in there," Cooper said. "But for us it was tough because you talk about the speed in that game, and we had to fight through the last 50 minutes with five defensemen. That's a grind."

With Theodore out and a game that went long into 3-on-3 OT, Cale Makar skated more than 28 minutes and defense partner Devon Toews just under 26.

"In a game like that at that pace, having five defensemen up and down the ice, I can't say enough about what those guys did right till the end," goaltender Jordan Binnington said. "It's really tough to see Shea go down like that, but it happened and sometimes things happen like that and it's how you handle it."

Kempe, who also scored for Sweden, was not aware his hit injured Theodore.

"I didn't know, actually, either until the intermission when they came in and told me," Kempe said. "I can't even remember the hit to be honest, so I'm going to have to go back and look."

Philadelphia's Travis Sanheim figures to slot in for Theodore after being a healthy scratch against Sweden. He is the only other defenseman on the roster because each team was able to bring only seven.