The report from the team was that Timonen would need four-to-five weeks to recover. There was no mention whether surgery would be needed.
Timonen is the fifth Flyers defenseman to have his season ended early, joining Nicklas Grossmann (concussion), Braydon Coburn (shoulder), Andrej Meszaros (shoulder) and Bruno Gervais (torn stomach muscle). Kent Huskins, who has been out with a concussion since April 15 but recently reported feeling better, could return but is unlikely to play again this season.
Timonen had been the only Flyers defenseman to play in every game this season. Luke Schenn has missed one game, because of the flu.
The Flyers recalled veteran defenseman Andreas Lilja from their American Hockey League team on Tuesday, one day after recalling rookie blueliner Matthew Konan. One of them will replace Timonen in the lineup Tuesday against the Boston Bruins (7:30 p.m. ET, NBCSN, TSN).
Timonen is fourth among NHL defenseman with 29 points in 45 games. Of the 12 defensemen to skate for the Flyers this season, Timonen is one of two to have a positive plus/minus rating. His plus-3 is the same as rookie Brandon Manning, who has played three games.