Toronto Maple Leafs forward Matthew Knies did not return to Wednesday’s game against the Columbus Blue Jackets, after heading to the dressing room early at the end of the second period, and was ruled out at the start of the third period with an upper-body injury.

Knies threw a hit on Blue Jackets forward Kirill Marchenko, then collided with a linesman on his way down. Here is a video of the play in question:

Knies previously suffered an upper-body injury on November 20 against the Vegas Golden Knights on a hit from Zach Whitecloud, where he immediately headed to the locker room after crashing in the ice violently. The 22-year-old missed two games as a result of the hit.

It would be a tough loss for the Maple Leafs if Knies missed any time at all. Knies has become an integral part of the Maple Leafs, registering 18 goals and 31 points in 46 games, in a true breakout season where he’s been primarily paired with Auston Matthews and Mitch Marner. John Tavares is on injured reserve with a lower-body injury, Max Pacioretty is on injured reserve retroactive to January 18 and the Maple Leafs have faced several injuries across the board this season, while remaining atop the Atlantic Division.

“He’s a house,” Tavares said of Knies on January 7. “He’s a tough guy to move, so physically mature for his age. Just got real soft hands, I think he’s really shown that with his ability to handle the puck in tight areas and certainly in and around the net. It’s a nice combination for us.”

Nick Robertson took Knies’ place on Toronto’s top line alongside Matthews and Marner.

Prior to leaving the game, Knies registered one shot and three hits. Knies had been in tremendous form since Matthews returned to the lineup on January 4, authoring a five-point game against the Bruins in the best performance of his young career.