The forward was injured in a 3-1 loss to the Edmonton Oilers on Wednesday when he was hit along the boards by Oilers forward Josh Archibald 2:51 into the third period after making a pass.
"He was in here this morning," Maple Leafs coach Sheldon Keefe said of Thornton on Friday. "And yesterday. So his presence will certainly be felt in that way, for sure. But definitely, you'll lose a little bit of something in practices and games and all that. Obviously his presence and his voice is a big reason why we brought him here. We will still get some of those benefits with the life and the energy and the smile that he brings to the rink every day."
Thornton signed a one-year contract with the Maple Leafs on Oct. 16 after playing 15 seasons for the San Jose Sharks. The 41-year-old scored two points (one goal, one assist) in five games this season playing primarily on a line with Auston Matthews and Mitchell Marner.
Keefe also said Matthews won't play against the Oilers at Scotiabank Arena on Friday (7 p.m. ET; TSN4, SNW, ESPN+, NHL.TV).
"He's dealing with some upper-body soreness, and he's going to be a day-to-day situation," Keefe said. "I'm not too concerned. There was a possibility that he would play today but just wasn't feeling right in that sense today so we're going to give it a little bit more time."
Forward Nick Robertson was placed on long-term injured reserve Thursday. He is out at least four weeks with a knee injury sustained Jan. 18.
NHL.com staff writer Mike Zeisberger contributed to this report
