Marner fell awkwardly after getting tangled up with the stick of Flyers winger Carsen Twarynski off a draw early in the second period.
The 22-year-old struggled to the bench, but returned to the ice for another shift. However, he fell again on his own and left the game.
Marner took a skate during a commercial break midway through the second, but left without taking a shift.
He has not missed a game since his rookie campaign in 2016-17, but that’s about to change, as coach Mike Babcock announced after Saturday’s shootout loss that Marner will not play Sunday against the Chicago Blackhawks.
Babcock said he didn’t know the severity of Marner’s injury.
Marner has 18 points in 17 games this season.