Matthews is considered day-to-day and isn't expected to be held out long, Keefe adds.
When asked if the 23-year-old is suffering from the same injury as a wrist ailment that resulted in Matthews missing three games earlier this season, Keefe said "it's similar but not the same no," according to The Athletic's Jonas Siegel.
The forward was the first Leafs player on the ice for the morning skate Thursday, but he departed before it officially began. The team practiced with these lines without the sniper:
Matthews leads the league with 32 goals over 40 games, and he's also added 21 assists.