Marner hasn't been on the ice since scoring the game-winning goal in Toronto's previous game.
Mitch Marner missed his first game of the 2024-25 season on Tuesday.
The Toronto Maple Leafs confirmed that the club's leading scorer would be unavailable to the club and revealed that the player has a lower-body injury.
Marner's status for the game was in serious doubt when the star forward missed the club's last two on-ice sessions. Although initially cited as "maintenance" by the Leafs, it became clear that the forward's status to play was in doubt when the club moved Max Domi from center to the wing position to play in Marner's place.
Domi previously played in Marner's role as the first-line right-winger last season when Marner missed nearly a month due to an injury late in the season.
Toronto held a full morning skate ahead of their game against the Flames and Marner's absence was notable. Maple Leafs head coach Craig Berube was vague in describing what happened to Marner.
"Something happened in the game, I guess," Berube said of Marner, referring to the club's 4-3 win against the Edmonton Oilers on Saturday.
Marner had played in all of Toronto's 53 games before the game against the Flames on Tuesday. He leads the club with 70 points and 54 assists and is fourth in league scoring. The Leafs have two more games following the contest against Calgary before the league breaks for the 4 Nations Face-Off tournament. Marner was named to Team Canada. Although reports suggest Marner should be fine to play in that tournament, it's certainly something the team and player will be mindful of between now and the start of the tournament on Feb. 12.