Brendan Gallagher is dealing with headaches after returning to the lineup Thursday, and Montreal Canadiens coach Claude Julien said the forward will be evaluated by team doctors.
If the headaches are determined to be related to a recent concussion, Julien said Gallagher would be held out of the lineup when the Canadiens play at the Ottawa Senators on Saturday (7 p.m. ET; CBC, SN, SN360, CITY, TVAS, NHL.TV).
Gallagher missed four games after sustaining a concussion in a 3-1 loss at the Carolina Hurricanes on Dec. 31. He wore a tinted visor when he returned in a 4-2 loss to the Edmonton Oilers on Thursday, finishing with no points, four shots on goal and two hits in 17:19.
Gallagher reported the symptoms to the Canadiens on Friday morning and did not practice.
"What we're doing with him because he's had a concussion is making sure it's not a relapse," Julien said after practice. "At the same time, it could be a virus. So he's gone to see the doctor and we're being cautious with this situation because of what he's been through.
"If it's concussion-related, then there's no doubt he's out. We're going to always protect the player first before we force somebody like that into a lineup."
Gallagher is second on the Canadiens with 15 goals and tied for third with 32 points. He had an NHL career-high 33 goals last season.