Toronto Maple Leafs winger Mitch Marner left practice early on Tuesday after a collision with teammate Wayne Simmonds.
Head coach Sheldon Keefe says Marner left for precautionary reasons, and that he'll be re-evaluated Wednesday morning.
The development comes just over 24 hours before Toronto's season opener against the visiting Montreal Canadiens on Wednesday.
Marner was fourth in the NHL with 67 points (20 goals, 47 assists) in 55 games last season.