Montreal Canadiens forward Rene Bourque recently suffered a setback in his recovery from a concussion.
RDS reported on Saturday that Bourque left Thursday's skate early because he wasn't feeling well and hasn't returned to the ice since.
The 31-year-old suffered his concussion in late February. He had five goals and 10 points in 17 games up until that point in the season.
Bourque remains out indefinitely.