The Calgary Flames will be without Matthew Tkachuk Tuesday when they host the Edmonton Oilers. The forward is listed as day to day with an upper-body injury, Flames head coach Glen Gulutzan told reporters following the team’s morning skate.

Tkachuk had to be helped off the ice late in Sunday’s 5-2 loss to the New York Islanders after the back of his head smacked against the boards when he tripped over Mathew Barzal.

It’s unclear at this time the severity of his injury but, at least in the short term, it’s a huge blow to a Flames team that sits two points out of a playoff spot and has little room for error with 12 games remaining in the regular season.

Tkachuk has 24 goals and 25 assists, both career highs, in 68 games this season. The 20-year-old’s teammates were concerned when they saw him go down.

“We know how tough a kid he is,” Flames goalie Mike Smith said Sunday. “There have been instances this year where he’s done similar things, and he always seems to bounce right back up after, 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.”

Added captain Mark Giordano: “He doesn’t stay down unless he’s hurt, so that’s what is concerning. 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.”

Winger Chris Stewart, who was claimed off waivers from the Minnesota Wild in February, will draw into the lineup against the Oilers.