The incident occurred during the Sharks' 9-2 rout of the Rangers on Tuesday when Stuart was initially assessed a minor penalty.
Nash, who has a history of concussions, said he felt the effects of the blow.
"I have a headache," Nash told reporters. "It got worse. I'm concerned the way it feels."
The game was Stuart's season debut after he missed the opening two games with a lower-body injury.
He will be eligible to play again on October 17 when the Sharks visit the Dallas Stars.
(Writing by Jahmal Corner; Editing by Peter Rutherford)
- Sports & Recreation
- Ice Hockey
- Brad Stuart
- Rick Nash
- San Jose Sharks
- New York Rangers