Desjardins was injured midway through the third period of Saturday's 4-1 triumph over the Toronto Maple Leafs, which gave Philadelphia a three games to two lead in the Eastern Conference quarterfinal series.
A former Flyers' captain, Desjardins is a close second on the team in average ice time at just over 27 1/2 minutes in five playoff games. He is sixth on the team in scoring with two goals and an assist.
"I think the biggest change for us will be on the penalty-kill," Coach Ken Hitchcock said. "Eric kills a lot of penalties for us."
Rookie defenseman Jim Vandermeer will take Desjardins' spot in the lineup on Monday in Game 6 and will make his NHL postseason debut.
"It's my first NHL playoff game, so I'll have some nerves there," the 23-year-old admitted.
Vandermeer had two goals and an assist and was a plus-9 in 24 games during the regular season. He spent most of the campaign with the Flyers' American Hockey League affiliate.