The NHL is reviewing a hit by San Jose Sharks defenseman Brad Stuart to the head of New York Rangers forward Rick Nash during Tuesday night's game in San Jose, Calif.
A hearing was to be held by the NHL Department of Player Safety on Wednesday.
Nash played several more shifts after the hit but then left the game and didn't return for the second period of the Rangers' 9-2 loss to the Sharks.
"I have a headache," he said, according to MSG Network. "It got worse. It was a head shot. I'm concerned the way it feels."
Nash has a history of concussions, but there was no immediate word on his condition and whether he might be sidelined.
Stuart received a minor penalty for elbowing at 2:23 of the first period. Replays appeared to show Stuart's shoulder hitting Nash's head.