Chris Pronger's mystery virus has turned into a real headache that won't go away, literally.

Four missed games and no better, the Flyers captain decided to have knee surgery late last month. Afterward, Pronger mentioned that he'd had a baseline concussion test to treat the illness that had been called a virus.

The latest update, provided on Friday by Flyers general manager Paul Holmgren, is worse:

Pronger, 37, will be in Pittsburgh next Wednesday to be examined by Sidney Crosby's doctors for post-concussion syndrome.

"I think over the last few days he's had some difficulties, a fairly persistent headache, just sluggish feeling," Holmgren said. "So we're just trying to do the right thing here and get him checked out by the doctors in Pittsburgh and just see what we're dealing with. Is it a concussion? I don't know that we know that. We want to get a better idea, obviously."

Holmgren also announced that rookie forward Brayden Schenn, sidelined the last two games with what the team had called an upper-body injury, has a concussion.