MONTREAL -- The Montreal Canadiens will most likely be welcoming a versatile piece back to their lineup Tuesday night when they play for their playoff lives in Game 6 of the Eastern Conference quarterfinal-round series against the Boston Bruins.

Rookie sparkplug David Desharnais will not be able to dress with a sprained knee, according to various media reports, and his spot will likely be filled by Swiss defenseman Yannick Weber.

Weber played on the wing in Game 2 of the series when Andrei Kostitsyn was forced to sit out with a foot injury, and he responded by scoring a key insurance goal late in Montreal's 3-1 victory.

"If I get the opportunity to play, I'll be ready," Weber said. "I got a lot of confidence in the last game I played in Boston, so I'll just try to do the same things."

Weber only found out he would be playing in Game 2 after the warm-ups, and he said the situation will be the same Thursday night.

Weber practiced Monday on the point on the Canadiens' top power-play unit, to the right of rookie P.K. Subban, and he brings with him a booming shot that he can release quickly with accuracy.

The spot opposite Subban is normally filled by defenseman James Wisniewski, who is also questionable for Game 6.

Wisniewski hurt himself at some point in the second period of Game 5 and sat out nearly the entire third period and half of the first overtime period before returning at around the eight-minute mark and finishing the game.

If he is unable to play, it could mean Paul Mara would be inserted into the lineup, and Jaroslav Spacek would switch sides to play to the right of Roman Hamrlik on Montreal's second pairing.

While the potential loss of Wisniewski would most definitely hurt the Canadiens' chances of extending this series to a deciding Game 7 in Boston on Wednesday night, the all-but-assured absence of Desharnais should not be understated as a major factor.

In his first 34 games with the Canadiens since his call-up on New Year's Eve, Desharnais notched 22 points, putting him fourth on the team in scoring over that span behind only Subban, Wisniewski and Tomas Plekanec.

But he then finished the season without a point in his final nine games, suggesting he wouldn't be much of a factor in the series.

He wasn't through the first three games, playing limited minutes and struggling to keep up with the pace in his first taste of the Stanley Cup Playoffs. But in Game 4, the 5-foot-7 center emerged as a defensive force, helping shut down Bruins center Patrice Bergeron in the third period after he had racked up 7 shots on goal through 40 minutes.

In Game 5, Desharnais made an impact offensively when he was placed on a line with Scott Gomez and Brian Gionta to start the third period.

"He's had a good series," Bruins coach Claude Julien said. "You think about Martin St. Louis. Desharnais doesn't have the pedigree or the experience, but he certainly has the makings of becoming a player like that."

Except now, Canadiens coach Jacques Martin will not have that player available to him, which will put even more pressure on players like Gomez, Gionta, Plekanec and Michael Cammalleri to produce.

Cammalleri has picked up where he left off last spring, when he led the League in playoff goals with 13 in 19 games. Cammalleri has 7 points in 5 games, giving him one more than Bergeron to lead the series.

But Gomez, Gionta and Plekanec have only 8 points combined, and the Canadiens do not possess enough scoring depth to have much success if those three are not producing.

"Being an older guy, yeah, that's what's expected of you," Gomez said Monday. "The young guys are going to look up to you, look for you to lead."

Despite the Canadiens' desperate situation, the room was quite loose after Tuesday morning's optional skate. The benefit of the team's core leadership group having won five straight elimination games last spring was rather evident.

"I really think that if we play a good game that we'll win, I'm confident in that," Cammalleri said, perfectly calmly. "I don't find it stressful, I find it exciting. It's an opportunity, that's what it is."