CALGARY – Three NHL centres could have played for Canada's junior team but won't, leading to questions about the country's depth up the middle for the upcoming world junior hockey championships.

Ryan Nugent-Hopkins of the Edmonton Oilers, Ryan Johansen of the Columbus Blue Jackets and Sean Couturier of the Philadelphia Flyers were not released to try out for Canada by their respective NHL clubs.

When the players invited to Canada's selection camp hit the ice for the first time Sunday in Calgary, it looked like only six centres were competing for four jobs on the team.

But head coach Don Hay and Hockey Canada head scout Kevin Prendergast insist Canada won't be short at centre. As many as five who started camp on the wing can also play in the middle, Prendergast said.

"I would do wingers in the middle," Hay agreed Sunday prior to the first intra-squad game at night. "There's going to be guys that play out of position. There's going to be roles for different players. I think good players can adapt."

Prendergast has said the team wants two scoring centres and two more to play a two-way game.

Mark Scheifele of the Barrie Colts and Ryan Strome of the Niagara IceDogs are the frontrunners for two of the four jobs. While the world junior championship is considered a 19-year-old's tournament, they are both 18.

Scheifele, from Kitchener, Ont., played seven NHL games with the Winnipeg Jets and scored his first NHL goal before he was returned to the Colts. He is putting it out there that he wants to be the No. 1 centre on the Canadian team.

"I think it's definitely important to make goals like that," Scheifele said. "That's definitely my goal, to be the No. 1 centre. I'm going to do whatever it takes to do that."

Although Strome didn't appear in any regular-season games with the New York Islanders, they kept the Mississauga, Ont., native with the team until Oct. 13.

"They're high-profile young men," Hay said. "They've been exposed to the National Hockey League level and played in some exhibition games and some regular season games.

"They're like anybody else. They have to show us they can play a 200-foot game and be good on both sides of the puck and not just be an offensive guy, but a good defensive guy."

The Jets took Scheifele seventh overall in this year's NHL draft. While he's bigger than Strome at almost six-foot-two and 192 pounds, Prendergast says both have good hockey sense and distribute the puck well.

"If you put them in a race, they'd probably be tied," Prendergast said.

Scheifele has 13 goals and 23 assists in 19 games for the Colts since returning from the NHL.

Strome, the fifth overall pick by the Isles, has 16 goals and 17 assists in 32 games for the IceDogs. The six-foot, 183-pound forward is prepared to be a checking forward if that what it takes to make the team.

"Canada always plays a hard-nosed game and you can't take any shortcuts," Strome said. "Everybody's got to go out there and play the body and be gritty and that's what I plan to do. I'm not going to shy away from the physical stuff because in this tournament it will cost you."

Behind Scheifele and Strome, there's Strome's Niagara teammate Freddie Hamilton, Zack Phillips of the Saint John Sea Dogs, Michael Bournival of the Shawinigan Cataractes and Mark McNeill of the Prince Albert Raiders battling for jobs at centre.

Bournival, 19, was among the final players cut from last year's team.

"I came here confident because I was at the camp last year and I knew what happened during that camp," Bournival said. "I don't want to miss my chance this year. It's the only chance I have and I will give everything I have to make the team."

Phillips, from Fredericton, has never worn the Maple Leaf on the front of his jersey before. The Minnesota Wild property is also willing to alter his game to make the team.

"I've always been more of an offensive player, but I know to play on this team you're going to have to be able to play both ways," Phillips said. "It's something I have worked on this year and I think I can do a good job."

Boone Jenner of the Oshawa Generals, Ty Rattie of the Portland Winterhawks, Philip Danault of the Victoriaville Tigres, Quinton Howden of the Moose Jaw Warriors and Jonathan Huberdeau of the Sea Dogs can also move into the middle if reinforcements are needed there, according to Prendergast.

But Huberdeau did not skate Sunday. He broke a bone in his right foot Nov. 7, yet came to camp in the hopes the big winger will recover in time to play for Canada. The tournament opens Dec. 26 in Edmonton and Calgary.

Hay says Huberdeau was examined by team doctors and underwent physiotherapy after his arrival, but the head coach doesn't know when the Memorial Cup MVP will get on the ice.

Forty-two players reported to camp Saturday. Hay intends to thin the crowd with the first round of cuts Tuesday morning after watching the players in two intra-squad games. The remaining players face a team of university selects in an exhibition game that night.

Hay will announce Canada's 22-player roster Wednesday.

Scheifele and Strome just missed being teammates on the Colts. Barrie traded Strome mid-way through his rookie season to the IceDogs, while Scheifele didn't start his OHL career with the Colts until the following season.