No Tim Howard, no Carlos Bocanegra, no Steve Cherundolo, no Fabian Johnson, no Timmy Chandler, no Danny Williams, and, of course, no Landon Donovan.

It was the absences that were most conspicuous on the U.S. men's national team roster released by head coach Jurgen Klinsmann on Monday afternoon. The team he cobbled together for two crucial World Cup qualifiers against Costa Rica on March 22 and Mexico on March 26 is heavily diluted.

The games are important: after the dire 2-1 loss to Honduras in San Pedro Sula last month, the U.S. needs all three points against Costa Rica in Denver on Friday -- Klinsmann told FOX Soccer last week that the Denver match was a "must win." The USA could also really do with at least a point in Mexico City next Tuesday.

But a series of ill-timed injuries and illnesses have conspired to make an already daunting task a towering one, leaving Klinsmann scrambling to construct a competitive roster. An uphill battle might have become an even steeper slog.

"As you can see on the roster we had to deal with a couple -- well, not a couple, a lot more -- injuries over the last couple of days and weeks," Klinsmann said on a conference call. "But we have a roster together that gives us the confidence to approach both games very, very positively. We're not complaining about the situation and we take it as it is."

Goalkeeper and defensive pillar Tim Howard has a back injury. In his place will step Brad Guzan, who has made a good impression at Aston Villa of late, in spite of its relegation troubles. He will be backed up by the capable Nick Rimando and the young Sean Johnson.

Other holes and cracks in the squad aren't so easily patched, however. The list of defenders reads like it was assembled from a grab-bag. Long-time captain Carlos Bocanegra, who was surprisingly benched against Honduras, isn't on the roster at all. Bocanegra hasn't played regularly for his Spanish second division club Racing Santander in months but he was solid as ever in his most recent U.S. appearances. What makes his sudden ouster all the stranger is the near-biblical plague of physical hindrances afflicting the other defenders in the pool.

Ageless right back Steve Cherundolo has a knee injury. Timmy Chandler, his rival or understudy, depending on your perspective, has a hamstring issue. On the left, the incumbent Fabian Johnson has a hip problem while his backup Edgar Castillo isn't yet sufficiently recovered from his facial fractures to play. A logical emergency fill-in on either flank, Jonathan Spector, has an ankle injury.

Still, Klinsmann has never been prone to negativity. "I feel comfortable we are covered there," he said. "We have other options." Those options come in the form of backs Justin Morrow and Tony Beltran, of the San Jose Earthquakes and Real Salt Lake respectively, who have two U.S. caps between them and neither of whom has ever played in a World Cup qualifier. The ranks aren't much deeper between them in central defense, where Geoff Cameron and Omar Gonzalez, who didn't inspire much confidence as a pairing against Honduras, were called in along with Clarence Goodson and Matt Besler. Put together, those four have just 12 World Cup qualifiers under their belt. Goodson is the only one who has more than 12 total national team caps.

In midfield, a hamstring injury to Jose Torres and Danny Williams' illness leaves a group of nine, comprised of central midfielder Kyle Beckerman, Michael Bradley, Jermaine Jones and Maurice Edu. DaMarcus Beasley and Brek Shea are the left wingers. Graham Zusi seems slated for the right. And Joe Corona and Sacha Kljestan can play in any of the midfield spots.

The only line that's at full strength is the forwards. (Well, almost at full strength, since Landon Donovan hasn't returned from his sabbatical away from the sport yet.) Clint Dempsey played a half against Fulham on Tottenham Hotspurs' 1-0 loss on the weekend, his first action in almost a month following a calf injury, and was called up. So were Eddie Johnson and Terrence Boyd. Jozy Altidore and Herculez Gomez, meanwhile, gave a rare few reasons for optimism, as both are in fine form. Altidore scored his 25th goal of the year for AZ against Ajax last weekend. Gomez is playing regularly for Santos Laguna and has four goals in his last four games in all competitions.

Costa Rica and Mexico are dynamic teams that will mercilessly attack the American wings. This is as bad a time as any for the U.S. to be staffed by inexperienced third-stringers there. Nor does it help that of the core players who have dictated the team's identity in recent years, only Michael Bradley is completely healthy, and he's not been always been a starter for AS Roma recently at that, while Dempsey won't be fully match-fit. Both are a lone yellow card away from an automatic one-game suspension, which could rule them out of the Mexico game.

They say injuries present opportunities for others. If these emergency national-teamers don't seize those opportunities in the two upcoming games, it could mean leave the U.S.'s prospects of reaching the 2014 World Cup are left in a sorry state indeed.