Calgary Flames winger Matthew Tkachuk left Sunday's loss against the New York Islanders in the third period with an apparent head injury, though head coach Glen Gulutzan said he missed practice Monday for a maintenance day.

Tkachuk fell awkwardly into the boards on Sunday after getting tied with Islanders centre Mathew Barzal. He remained on the ice after the collision and left the game with the help of a trainer.

Tkachuk, along with Sean Monahan and Mikael Backlund, was missing from practice on Monday. 

"They all had maintenance days or they would have been on the ice," Gulutzan said of the three players. 

Tkachuk's teammates expressed their concerns about the 20-year-old after Sunday's game.

“It looked scary. I don’t know exactly how it is, but it seemed like he bumped his head,” winger Michael Frolik told the Calgary Sun. “Obviously, it’s sad to see him go down, but hopefully he’s going to be all right. We’ll see (Monday), I guess.

“He’s having a great season. He’s big on that power-play unit in front of the net and he’s always great around the net. It would be a big loss, for sure. Maybe he’s going to be OK, but obviously when he left the ice, it didn’t look good.”

“We know how tough a kid he is. There have been instances this year where he’s done similar things, and he always seems to bounce right back up after,” goaltender Mike Smith said. “So when you see him that slowly getting up, you’re obviously concerned.

“He’s been a big part of our team this year and a guy that is really hard to replace. Obviously, we know what kind of player he is and the energy he brings, so hopefully it’s nothing serious.”

“He doesn’t stay down unless he’s hurt, so that’s what is concerning,” captain Mark Giordano added. “He is one of our top players. Every night, he creates. He creates power-plays for us. He creates chances. He’s just a big part of our team, a top-six guy. So hopefully he’s OK.”

Tkachuk has 24 goals and 49 points in 68 games this season for the Flames, who sit two points out of the final wild-card spot in the Western Conference.

The Flames are expected to update Tkachuk's status after Monday's practice.