GOAL.COM (Ives Galarcep)

When asked on Monday about whether the U.S. national team had some concerns regarding its central defense, Bruce Arena sounded genuinely surprised by the question. The loss of regular starter John Brooks to injury a week ago wasn't good news, but as the coach made clear, the U.S. isn't lacking for center-back options.

Veteran starter Geoff Cameron is in the squad, and is expected to anchor the defense against Costa Rica and Honduras in the coming days. But Omar Gonzalez, Tim Ream, Matt Besler and Matt Hedges are all in the running for starting roles after having earned starts at different points this summer.

"I think we have five center backs in camp. We're in a good spot," Arena said. "Out of those five center backs, three of them were in the Gold Cup and the other two played the last time around so we’re in good shape there I think."

The Cameron-Brooks center-back tandem is widely regarded as the U.S. team's first-choice pairing, but Arena has used it just once in four World Cup qualifiers this year, and just twice all year. Arena has made full use of the U.S. team's center-back pool since taking over for Jurgen Klinsmann last fall, and his liberal use of central-defense options have helped instill confidence among the contenders for playing time, who all know they could get the call to start in the next week.

"I think Bruce has shown, even going back to the March friendlies, that there’s competition (at center back)," Ream said. "Even when [John Brooks] is in there’s competition. He’s not afraid to shuffle the pack and change things up and choose pairings that he sees as the optimal pairing for that match depending on what the strikers are doing, or the team as a whole that we’re playing."

Gonzalez had been a question mark for the upcoming qualifiers as recently as a week ago, but recovered from an undisclosed injury in time to start for Pachuca last weekend, clearing the way for his inclusion in the U.S. qualifying squad. Arena made it clear he has no concerns about Gonzalez's readiness to contribute.

Gonzalez is a leading candidate to start in one or both of the upcoming qualifiers, but Ream and Besler have both shown well at different parts of the summer. There is also the question of whether Ream or Besler might be a better fit next to Cameron because of the fact they are both left-footed central defenders. Arena downplayed that aspect of his options, though his track record of lineup selections suggests it does play a factor in his choices

"It helps. I don’t think it’s required," Arena said when asked if he preferred a left-footed left center back. "There's this guy Lionel Messi who plays on the right side (and is left-footed)."

U.S. goalkeeper Brad Guzan downplayed the significance of having a left-footed center back, particularly given the current group of U.S. central defenders.

"If the guy is comfortable with both feet, we’re talking about playing with the national team so it’s not like we’re talking about a rookie coming into MLS or somebody that’s never played a professional game," Guzan said. "The guys that we have in camp are good on the ball with both feet, and normally something like that it just comes down to, on a certain play or two, being able to adjust their feet, sort their feet out, and the guys we have in camp are able to do that."

Another wrinkle for the U.S. defense is the option of playing three central defenders in a 3-5-2 formation, like the Americans did in June's 1-1 draw with Mexico at Estadio Azteca. That tactical option was clearly implemented to deal with the challenges Mexico's attack presented, but the U.S. team's performance in that match suggests it is a setup we could see again.

"Obviously there was a decent amount of success down in Azteca. I can’t say definitively if we’ll see it again or not," said Ream, who started in the three-man defense against Mexico. "I think we did a pretty good job, enough so that it gives them something to think about and it gives them an option. It’s something that maybe we can tweak, even in the flow of a game. You might see it. We haven’t really discussed tactics up to this point, but I think it worked well enough that it’s definitely an option going forward."

A four-man defense seems more likely against Costa Rica and Honduras, but trying to determine which two center backs we'll see in those matches is much tougher to figure out. Arena has used the same center-back tandem in consecutive matches just twice this year, with the Gonzalez-Besler pairing having started three of the U.S. team's six Gold Cup matches, including the final two.

As things stand, a Cameron-Ream tandem seems like the favorite to start against Costa Rica on Friday, but given the fierce competition at the position, it's far from a lock.

"It’s nice to have competition. It keeps you on your toes," Ream said. "It keeps that competitiveness there. I think that’s important, not just at the club level, but at the international level.

"If you know you’re coming in and not going to get a shot, and a chance to play. It’s kind of demoralizing to be honest with you. I’ve been there, I’ve experienced that. It’s nice to come in and know that you have a very good chance of playing in one of the two games."