SOCHI -- Martin St. Louis has built a career as a high-energy player, a water bug on the ice who keeps his powerful legs moving at all times to overcome his lack of size with his overwhelming will.

A player like that requires a certain degree of rhythm to play his game.

But even though St. Louis will be in the lineup for Canada when it plays Latvia in a 2014 Sochi Olympics quarterfinal Wednesday (noon ET, MSNBC, CBC), the Tampa Bay Lightning captain will have trouble creating that rhythm he so desperately needs to be effective.

"He's just a good, veteran player," Canada coach Mike Babcock said. "The reality is we dress 13 forwards each game. One guy hardly gets on the ice. It's a hard, hard situation for people that play 22 minutes [in the NHL]. That's the way it is. You've got to find a way to help out when you get a chance."

St. Louis, who was scratched in Canada's Group B finale Sunday against Finland, has no illusions of playing any role other than that of 13th forward and knows his opportunities will likely be few and far between.

"I mean, obviously you're out there with different guys all the time," St. Louis said. "But you understand it's a possibility you're going to be in that situation coming to these tournaments. You stay ready, you wait for your opportunity."

Canada did not run lines at its pregame skate Wednesday, but St. Louis was rotating with Rick Nash at right wing on a line with John Tavares and Patrick Sharp at practice Tuesday. It's also possible he's given spot duty on the power play with Ryan Getzlaf and Corey Perry, though it was Jonathan Toews who practiced on the power play with them Wednesday after St. Louis was in that spot Tuesday.

Babcock has already stated he doesn't like using his 13th forward and seventh defenseman exclusively on special-teams units because of how difficult it is to play in an important situation after sitting for so long.

"You feel bad for him," Babcock said. "He gets out there, he's frozen to death. That's the way it is."

St. Louis admitted the physical challenge of getting spot duty slightly outweighs the mental one, though each is difficult. He said the fact you don't really know when your next shift will come makes it hard to be sharp when your name gets called, and then the physical challenge of getting your legs moving kicks in.

"You're trying to go out there and earn another shift, I guess," he said.

That's exactly what Jeff Carter did when he was in the position St. Louis finds himself in now.

Carter was the 13th forward for Canada's second game of the tournament against Austria, but he scored three straight goals in the second period of that game and has been on a line with Jonathan Toews and Patrick Marleau ever since.

Carter entered that 6-0 victory at risk of dropping out of the lineup entirely and wound up with a spot on the only consistent forward line Canada has had.

"I think it's gone well with us," Carter said. "We're all kind of similar players. It's not too fancy; it's kind of straight lines and using our speed and getting pucks to the net.

"It's made it kind of easy for us to come together."

Carter's fortunes turned when he stepped out of the penalty box and a pass from an Austrian player happened to hit his skate. The puck bounced to Sidney Crosby, who set up Marleau for a chance that went off the post.

Carter was there to tap the puck into an empty net, and then he scored another one on his next shift. Just like that, his spot in the lineup was solidified.

And it all began with a lucky bounce coming out of the penalty box.

Perhaps a similar bounce will benefit St. Louis in some way Wednesday.

Here are the lines Canada is expected to use against Latvia:

Chris Kunitz - Sidney Crosby - Patrice Bergeron

Patrick Marleau - Jonathan Toews - Jeff Carter

Jamie Benn - Ryan Getzlaf - Corey Perry

Patrick Sharp - John Tavares - Rick Nash/Martin St. Louis

Duncan Keith - Shea Weber

Marc-Edouard Vlasic - Drew Doughty

Jay Bouwmeester - Alex Pietrangelo

Dan Hamhuis

Carey Price

Roberto Luongo

Scratched: Matt Duchene, P.K. Subban, Mike Smith