MONTREAL - In a stunning development, the Flyers will have to do without their captain and top defensive player, Chris Pronger, for the rest of the season and the playoffs because of post-concussion syndrome.

The club made the grim announcement in a statement during the first period of Thursday's game in Montreal.

Pronger, 37, met with concussion specialists Joseph Maroon and Micky Collins in Pittsburgh on Wednesday.

In a statement, general manager Paul Holmgren said Pronger would be shut down based on the recommendation of the doctors.

"Chris will continue to receive treatment and therapy with the hope that he can get better," Holmgren said.

Over the long run, how will the injury affect a Flyers team that has excelled even though numerous key players are sidelined?

"I don't think it's crippling," Peter Luukko, president of the Flyers' parent company, Comcast-Spectacor, said in a phone conversation. "We will certainly miss one of the better players in the league, but you see how the team has played without him. We'll just move on."

 Referring to Pronger, coach Peter Laviolette said: "First and foremost, we wish for him to have good health. Anything after that, we'll sort it out." 

Entering Thursday, the Flyers were 11-4-1 without Pronger this season and 8-3-2 with him.

Pronger injured his right eye Oct. 24 when struck inadvertently by the stick of Toronto's Mikhail Grabovski. He missed six games, returned to the lineup, and played five games. The veteran defenseman was then sidelined because the Flyers said he was suffering from a virus.

Eighteen days later, however, the team said he had concussion-like symptoms. That led to Wednesday's visit to the Pittsburgh specialists.

 Winger Wayne Simmonds called the loss of Pronger "devastating. He's an all-star defenseman, and I think he's the best defenseman on the back end, [but] we've played well without him. . . . We have good leaders on this team. Obviously Prongs is our captain and one of our great leaders, and we have other guys like Kimmo [Timonen] and Cobes [Braydon Coburn] and Harts [Scott Harnell] and Jags [Jaromir Jagr]. Those guys are awesome, and we just follow." 

Pronger, who was not available to comment, does not remember getting hit in the head after his brief return to the lineup.

But Douglas Smith, director of the center for brain injury and repair at the University of Pennsylvania, said Monday that "any kind of hit" to another part of the body could have triggered the problem because the head may have already been injured.

"Another hit can send spasms" to the head, he said.

Pronger underwent surgery on his left knee Dec. 2 - a little more than five weeks after his eye injury. It was his fifth surgery in 16 months.

For the time being, the Flyers defense will continue to include rookies Marc-Andre Bourdon and Kevin Marshall, along with veterans Timonen, Coburn, Matt Carle, and Andrej Meszaros.

Promising Erik Gustafsson, another rookie, is expected to return from wrist surgery in a week to 10 days. Gustafsson had been impressive in five early-season games, and he will likely replace Marshall.

The defense has played superbly in Pronger's absence, as have the defensively responsible forwards.

"Obviously, he's a big part of what we're trying to accomplish," winger Matt Read said. "But when you're missing a key player, you just have to get tighter as a group and play better as a team. Take more of his responsibility as a group and do as much as you can."

Asked if he felt a trade was necessary and if the Flyers would name a temporary captain for the rest of the season, Holmgren was blunt.

"I have not had enough time to digest the news where we could answer those questions," he said in a text message.

In addition to Pronger, Claude Giroux and Brayden Schenn are sidelined by concussions. In the NHL, a total of 23 players are out with concussions or concussion symptoms.

Pronger has five years left on a seven-year $34.45 million extension. Now there are questions - big questions - about whether his Hall of Fame career will resume.