Lightning All-Star defenseman Victor Hedman left Thursday's game against the Flames with what appeared to be a left knee injury.

Hedman left the ice with 13:44 remaining in the second period after a collision with the Flames' Garnet Hathaway. Hedman was attempting a hit along the boards when Hathaway's right leg made contact with Hedman's left knee, causing it to turn awkwardly. 

Hedman, who has registered a plus-22 since Dec. 1, needed help getting off the ice and was seen limping on the way to the locker room.

A Norris Trophy finalist last season, Hedman entered Thursday's game averaging a career-high 25:57 average ice time.