Canada opens its Olympic men's soccer qualifying campaign this week, knowing that the road to London is short but very, very difficult.   

Four games in 10 days will determine whether the Canadian men can end their 28-year absence from the Olympic soccer scene.   

And coach Tony Fonseca has had essentially just eight days to assemble and mould a very young team.   

"It is what it is," Fonseca said philosophically. "We'll take it.   

"One good thing about Canadian [soccer players] is that they know that nothing comes easy for them. Everything requires a lot of concentration, a lot of work and a lot of desire. And this group is very focused, is very keen to take the opportunity. And obviously they're not going to let it go."   

Canada opens the eight-team under-23 tournament Thursday against El Salvador in Nashville.   

Only two teams from the CONCACAF region, which covers North and Central America and the Caribbean, will move on to London. So the Canadians have to make the final.   

Canada has been placed in Group A along with Cuba, El Salvador and the powerful Americans. Group B, based in Carson, Calif., features Honduras, Mexico, Panama and Trinidad and Tobago.   

"It's huge," Fonseca said of the Olympic qualifying hurdle his team faces. "We all know that.   

"Qualifying for the Olympics, it's a very tough challenge. And not just because of the level of competition that you have to face."   

Just getting players into camp is hard. The qualifying tournament does not fall under FIFA rules forcing teams to release their players.   

Fonseca, a former under-20 coach, is very familiar with the talent at hand. But the pre-tournament camp in Florida has been his only time with the team since March 2011. In all, the under-23 side has had just two camps in 2010 and two in 2011.   

Fonseca's preliminary roster includes some familiar names: defender Doneil Henry and defender-midfielder Matt Stinson from Toronto FC and former Toronto and San Jose Earthquakes defender Nana Attakora.   

Attakora (currently unattached), forwards Marcus Haber (St. Johnstone, Scotland) and Randy Edwini-Bonsu (Eintracht Braunsweig, Germany) and 17-year-old midfielder Samuel Piette (FC Metz, France) have spent time with the senior national team.   

Bryce Alderson and Russell Teibert, both of the Vancouver Whitecaps, have made their mark in national age-group teams.   

But Toronto FC defender-midfielder Ashtone Morgan and Energie Cottbus defender Adam Straith were apparently unavailable to Fonseca.   

The Canadian coach has tried to take the diplomatic route with clubs.   

"We just try to bring some sense to the table, tell people at the clubs how this is a very important step in players' development," he said. "Playing internationally, it's a fantastic opportunity to take the players' development to the next level."   

Fonseca's team is very young. While this qualifying round extends to players born in 1989, only five players on Fonseca's pre-tournament roster were born that year. Ten were born in 1990, five in '92, one in '93 and two in '94 (Piette and Alderson).   

Fonseca says the youth movement was deliberate.

"We see it as a great opportunity to give experience to this young group. We see talent moving forward," he said.   

"For years we've been talking about our young generation as not having enough experience internationally," he added. "And obviously that's something that we want to change for future.   

"We wanted to give the talented group more experience, more games internationally so they can actually equip themselves for being successful in the future and for us as a nation. ... I think this is the best thing that we can do right now."   

Senior coach Stephen Hart is on hand to monitor the players' progress.   

While Fonseca sees great potential, he also acknowledges some of his players are in good environments but not playing much.   

Consequently he sees one of the biggest challenges facing his team is maintaining their concentration for 90 minutes at this level.   

"Other than that, physically they will compete. But again it will be a tough competition and they have to really be on top of their game if they really want to do well."   

Haber is the lone returning player from the 2008 CONCACAF men's Olympic qualifying tournament. Canada came within one win of qualifying for Beijing, losing 3-0 to the U.S. in the semifinals.   

This American squad is brimming with talent. Of the 19 named to coach Caleb Porter's initial roster, 13 come from MLS clubs. Eight have played for the senior U.S. team.   

The U.S. squad includes Philadelphia Union midfielder-forward Freddy Adu, the only player with previous experience in qualifying, and FC Dallas forward Brek Shea, who has appeared in all 10 American senior games under coach Jurgen Klinsmann.   

The American roster also includes Canadian-born forward Teal Bunbury (Sporting Kansas City).   

"There are no easy teams but definitely the U.S. is a very strong contender," said Fonseca.   

"I think the three of us [in Group A] below the U.S. are in the same boat," he added. "It's going to be three teams fighting for second spot, that's the way I see it."   

Should Canada finish second, it will meet the Group B runner-up with an Olympic berth on the line.   

Canada has gone 1-1 in pre-tournament friendlies, defeating Trinidad and Tobago 1-0 on an Evan James goal and losing 1-0 to the Fort Lauderdale Strikers.