Matthew Knies was injured in the second period of Toronto's game Wednesday against the Columbus Blue Jackets.
Knies struggled to get up from the ice after colliding with Blue Jackets forward Kirill Marchenko and did not return to the game.
Knies was ruled out with what the Maple Leafs called an upper-body injury.
Leafs head coach Craig Berube said he had "no immediate update" on Knies' status Wednesday night.
Leafs reporter Nick Alberga reports Thursday that Knies is out day-to-day with a knee injury. The injury is not considered serious.
The Maple Leafs have yet to comment on Matthew Knies' injury status.
It's a positive for the Leafs, who appear not to be losing Knies long-term, as they have already recently lost John Tavares in the top six.
The Leafs have struggled with injury concerns all season, especially at forward, where, along with Tavares and now Knies, also having been injured, include captain Auston Matthews twice.
Currently injured forwards for the Leafs include Max Pacioretty, Calle Jarnkrok and Connor Dewar.
Luckily for Toronto, the injury to Knies appears to be just a minor bump in the road; with no serious concern, he looks to be back soon for Toronto.
The 22-year-old has 18 goals and 31 points in 47 games this season.
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