The Flyers on Tuesday revealed that veteran defenseman Chris Pronger underwent arthroscopic surgery on his right knee last week.
General manager Paul Holmgren called the procedure "minor" and said Pronger would be ready when camp opens Sept. 17 in Voorhees.
The Flyers said his surgery was to "remove loose bodies" in the knee. He has already started his rehab.
Pronger's knee problem, however, may explain why the Flyers are so heavy on defensemen; they have eight on their roster.
Pronger will turn 36 on Oct. 10.