It was a scary moment for Max Pacioretty and Canadiens fans.

Montreal's top forward left Sunday's game against the Florida Panthers after falling and hitting his head into the boards during the first period.

​Pacioretty was hit by Panthers defenceman Dmitry Kulikov, leading him to lose his balance and land awkwardly with the side of his head slamming into the boards. He looked woozy as he was helped off the ice.

Kulikov was assessed a two-minute penalty for interference on the play.

The Canadiens announced he would not return.

It could be a serious issue for playoff-bound Montreal as Pacioretty leads the team in goals with 37 and in points with 67.

The 26-year-old has suffered concussions in the past including in March 2011, after a hit by Boston's Zdeno Chara.

Contact by the Florida's defence has resulted in two other star players leaving games this season.

Kulikov was suspended for four games after hitting the Stars' Tyler Seguin in a game on Feb. 13, which caused a serious knee injury. Seguin missed three weeks before returning March 7 against the Lightning.

Panthers defenceman Alex Petrovic cross-checked the Blackhawks' Patrick Kane on Feb. 24, leading to a nasty crash into the boards.

Kane left the game and was later diagnosed with a broken clavicle. He is still unable to play. Petrovic was given a minor penalty, but received no suspension for his actions.