When and Where: The Concacaf men's Olympic qualifying match gets under way from Nashville, Tenn., at 9 p.m. ET Monday. A live stream is available with a free registration at ConcacafTV.

Preview: Following Saturday's shock 2-0 defeat to Canada, the U.S. under-23s face a crunch match against El Salvador, needing a win to guarantee keeping their hopes alive of qualifying for the semi-finals and thus the Olympics.

Despite its potential significance, U.S. coach Caleb Porter tried to downplay the significance of the Canada defeat following the game.

This isn't the end of the world, said Porter, according to the U.S. Soccer Web site. This isn't the way we wanted it to play out, but everything is still in our hands. If we beat El Salvador, then we're though.

But in private Porter will surely admit that he expected the U.S. place in the semi-finals to already have been secured by this stage and would have hoped to be able to rest several players against El Salvador.

But having already lost Juan Agudelo through injury during their opening win over Cuba, Porter cannot afford to rest the likes of Brek Shea and Freddy Adu with the humiliation of failing to qualify from a group they should have topped with something to spare staring them square in the face.

The prospect that the U.S. should not even contemplate at this stage is that even if they win and progress they could well be left with a semi-final encounter with their fiercest rivals, Mexico.

Only the winners of the two semi-finals will qualify for the London Olympics this summer.

But after such an abject display against Canada, purely beating El Salvador is challenge enough, for now.

El Salvador sit atop Group A, having opened with a 0-0 tie with Canada, before disposing of Cuba 4-0.

A draw for the U.S. will leave them hoping that Canada go down to Cuba in the other final Group A game on Monday -- an unlikely prospect given Canada's so-far impregnable defense and Cuba's 10 goals conceded in two games thus far.

Team News: Juan Agudelo returned to the New York Red Bulls on Sunday after tearing the meniscus in his left knee against Cuba. Teal Bunbury got the nod in place of Agudelo against Canada, but was given the hook for Terrence Boyd early in the second half. Porter may well give Boyd a chance from the start this time around.

With everything on the line against El Salvador, Porter has little choice but to name a largely unchanged lineup, meaning fatigue could well be a factor.

Prediction: For a U.S. team stacked with talent, it is that they even find themselves in this do-or-die position. The notion of the nation's finest under-23 talent failing to get through the group is simply unthinkable.

Agudelo is undoubtedly a loss, but there should still be enough ability in advanced positions for the U.S. not be unduly hampered. But the U.S. has continued to fail to inspire confidence with their defensive work, which means that this could well be an extremely nervous night for all connected to the team.

U.S. U23 2-1 El Salvador U23