"This has been an issue probably for the last month or so for him that's been nagging," general manager Paul Holmgren said in a conference call. "He's been playing through it up until this recent bout with a virus.
"We kind of believed that through continuing rehabilitation that he's been doing on that - that he does on a daily basis, anyway - and some medicine that it would start to feel better. Some of the loose bodies in there are becoming a little bit of an issue, and we felt it was better to get it taken care of now."
Holmgren called this surgery, Pronger's sixth surgical procedure in a 16-month span, "a maintenance thing more than anything." It is important to point out that when Pronger had a similar knee operation in July 2010, he missed the entire 2010-11 training camp in September and the first two games of the season.
Pronger, 37, already has sat out 11 games this season with various injuries, and he missed 32 games last season. He still has 5 years remaining on a 7-year, $34.5 million extension he signed in 2009.
When Pronger has been healthy this season, he has been a force. He has 12 points in 13 games and was on pace for his best offensive season in more than a decade.
Holmgren said he is not worried about Pronger's future health, as his knee structure is "fine" and there is "plenty" of cartilage on both sides of the knee.
Pronger was not available for comment yesterday.
"We're worried, because he's going under surgery, yes," Holmgren said. "But long-term, I still think Chris has a lot of miles left on his body. I think this time, the only thing we can go by is what doctors tell us, and it's just a question of cleaning up some of those bodies.
"And based on the way he takes care of himself and prepares, I think he'll be fine."
The important question is whether the Flyers will be fine until Pronger returns. They're already missing Andreas Lilja, also 36, for the next 6 weeks with a severe high-ankle sprain. Both players will be added to the long-term injured reserve today to give the team a cushion on salary cap.
For the short term, not only has HBO lost a top character in its "24/7 Road to the Winter Classic" reality series, but the Flyers are in a world of hurt on defense. For now, they have recalled defenseman Kevin Marshall from Adirondack, and he will temporarily round out the defensive roster with fellow rookie Marc-Andre Bourdon.
For the long term, Holmgren likely needs to make a trade to bring in depth replacements. It's tough to be successful on a nightly basis while asking two rookies to play nearly 30 minutes per game.
Other defensemen with experience in the system - such as Matt Walker and Oskars Bartulis - would first need to clear re-entry waivers, where they would be subject to a claim at half their salary-cap price. Bartulis, 24, almost surely would be claimed for $300,000 and the Flyers would be stuck with the other $300,000 as a salary-cap penalty without anything to show for it.
With Pronger and Lilja on the long-term injured reserve - where they will need to remain parked for the next 10 games or 25 days - Holmgren will have about $4.28 million in cap space to acquire a player or two. That number could grow to more than $5 million if Andreas Nodl, who also was waived yesterday, is claimed on waivers or sent back to Adirondack.
"We're talking about a lot of things in here," Holmgren said when asked about a trade possibility. "I think initially we'll just recall Kevin and try to figure out where we're at at that point."
With room to fit him under the salary cap, the Flyers recalled forward Brayden Schenn, who was sent to Adirondack last week after nursing a foot fracture for 4 weeks.
Schenn had two goals and two assists in three games last weekend for the Phantoms. He is still searching for his first NHL goal.
Forward Andreas Nodl was placed on waivers only 2 days after leaving the Flyers' loss to the Rangers with an upper-body injury. Holmgren said he was "fine" after getting checked out by team doctors on Sunday.
Nodl, 24, has one assist in 12 games. He had 22 points in 67 contests last year. Aside from being a healthy scratch, Nodl has dealt with three to four separate injuries this season.
"Andreas hasn't played much," Holmgren said. "We'll just gauge interest and see what happens. We'll decide his fate tomorrow after we find out whether he clears or not."
Nursing an aggravated groin injury, Jaromir Jagr skated by himself, and the Flyers are "taking it a day at a time with him," Holmgren said. Jagr could play Friday in Anaheim . . . James van Riemsdyk (upper body) did not skate. Holmgren said he is a "longshot" to play this weekend, but will know more about his status today after visiting doctors . . . The Rangers unveiled their Winter Classic jersey yesterday, an off-white vintage look with their 1926 logo . . . After Jody Shelley said Rangers forward Brandon Dubinsky "plays like a little weasel" in HBO's preview, Dubinsky fired back in the New York Daily News, saying, "It won't be long before [Shelley] is out of the league, because he's a terrible hockey player."
For more news and analysis, read Frank Seravalli's blog, Frequent Flyers, at www.philly.com/FrequentFlyers. Follow him on Twitter at http://twitter.com/DNFlyers.