The Flyers, who play Monday in Ottawa, are 2-5 without Lecavalier, who could miss 13 more games.
That means he may miss a total of 20 games, or about a quarter of the Flyers' season.
The next month, then, figures to be a huge character test for the Flyers to stay close in the Eastern Conference playoff race until Lecavalier returns. Holmgren said he expects others to "step up" in Lecavalier's absence.
The Flyers will not recall a player from the AHL Phantoms until late this week, and Tye McGinn is a leading candidate. Holmgren said the Flyers will not pursue a trade.
At least that's his stance for now.
Despite missing seven games, Lecavalier is tied with Matt Read for the team lead with nine goals.
Without Lecavalier, Michael Raffl, who has no goals in 17 games, has moved from the second to fourth line.
Lecavalier skated in Dallas on Saturday morning but was not himself, assistant general manager Ron Hextall said. "I don't believe it aggravated it, but it didn't help," Holmgren said.
The Flyers are 2-2 on their six-game, 13-day road trip, including Saturday's 5-1 loss in Dallas.
The Flyers scored a 5-0 win in Ottawa on Nov. 12, a game in which Steve Mason registered his first shutout with the team; they are 2-0 against the Senators and have outscored them, 10-2.
Ottawa is 11-14-5 and just 4-8-3 at home.
"We obviously can't take them lightly, even though we beat them a couple games," Schenn said. "We know they're going to come out hard."
Schenn (seven straight games), Jake Voracek (12 straight), and Wayne Simmonds (six straight) are in goal-scoring droughts.
The Flyers (13-14-2) have lost three games when they have had a chance to get over .500, including Saturday's defeat in Dallas.
"It's a work in progress. We need to be a more consistent hockey team," coach Craig Berube said. "We need the guys to understand that . . . you can't take nights off."
Breakaways. Berube said he expects defenseman Kimmo Timonen to be able to play Monday; he left Saturday's game with an unspecified injury in the second period. . . . Surprisingly, Zac Rinaldo did not have an NHL hearing for his attack on Dallas' Antoine Roussel on Saturday; the Flyers winger was given 27 penalty minutes, including a game misconduct. . . . Because a junior team had ice time scheduled, Sunday's practice was held at 8:30 a.m. "It was early, but I thought the energy was good, the intensity was good. It was a good sign," Berube said. . . . Bobby Ryan (Cherry Hill) leads Ottawa with 14 goals.