STANFORD, Calif. >> Matt Besler and Geoff Cameron might hear it from every angle if they were paying any attention or had a moment’s spare time. They could be reminded every day that this is the first time since 1990 the U.S. heads to a World Cup with no central defenders having played previous minutes in soccer’s showcase event.

And that makes an already daunting task in Group G much more challenging for the Americans, who face Ghana, Portugal and Germany next month in Brazil.

The competition for spots on the Americans’ back line is fierce, leaving no time to analyze the group’s inexperience.

“For us, there’s nothing we can do about it,” Besler said before Sunday’s training at Stanford Stadium. “We can’t change the fact that we’ve never experienced a World Cup. We’re looking at it as a great opportunity. We’ve never done it before but everyone is excited and really hungry to prove that we belong here and that we can do well.”

Nobody knows how the foursome will look for the team’s World Cup opener June 16 against Ghana in Natal, yet coach Jurgen Klinsmann will get a glimpse during an exhibition against Azerbaijan on Tuesday night at Candlestick Park. He has several choices for each defensive spot.

If there are concerns with Omar Gonzalez, who tweaked his left knee during a May 3 game with the Los Angeles Galaxy against Colorado, Klinsmann might go with Cameron in the middle alongside Besler. Gonzalez has since returned to full training.

“I think the competition is healthy, and it’s definitely alive and well here,” Gonzalez said. “Before I got injured, I was probably the fittest I’ve been in a very long time.”

Cameron plays right back for Stoke in the Premier League but insists he only needs a couple of reps at center back in practice, scrimmages or exhibitions to find a groove again.

“When you’re playing against Man United, Chelsea, Everton, Tottenham, you’re playing all the big boys every single weekend against the best competition, there’s no room for mental errors, there’s no complaining about how tired you are or this or that because the games come so quick,” Cameron said. “For me, it was a learning process the first year. As the second year comes, you get more comfortable, you’re confident going into the other stadiums.”

Besler, the 27-year-old Sporting Kansas City star who was the 2012 MLS Defender of the Year, has played in the middle with both Cameron and Gonzalez.

Cameron and Besler very well could start in the center back spots for the opener. Fabian Johnson or Timmy Chandler might play right back, though Johnson said he has seen regular time there.

“I played right back in all the scrimmages so I’m ready for this position,” Johnson said Sunday.

DaMarcus Beasley could be on the left as he looks to become the first American to play in four World Cups.

“It is different playing with different guys. Everyone has different styles,” Besler said. “I think as a team we play the same but when you have different guys back there you have to make little adjustments depending on who’s back there. But for me I have experience with both. I’ve played in World Cup qualifiers with Geoff, with Omar. I feel comfortable with anyone, really.”

If midfielder Jermaine Jones is suspended at some point for accumulation of yellow cards, Klinsmann might call upon Johnson in the defensive midfield.

While experience on the defense would certainly be preferred at this stage, goalkeeper Tim Howard will help everyone get up to speed.

“All things considered, of course you’d like to have some guys back there who understand the rhythm and the pacing and the difference of a World Cup,” said Alexi Lalas, a starting U.S. defender for the 1994 World Cup, former MLS general manager and current analyst. “This decision was made a long time ago, regardless of the final personnel, you knew you were going to have some World Cup inexperience out there. And we still don’t know how the back four is going to look.

“With that being decided and the veterans no longer being part of the scene, it was about getting some sort of understanding, communication and comfort with the defense. That’s really a much more important piece considering there’s not going to be World Cup experience.”

Cameron is considered a central defender by Klinsmann.

“I’ve said that over three years I think his best position is center back,” Klinsmann said. “And it’s good to know he can play right back, too, and it’s good to know he can play a No. 6, too. Still I think his best fit, his best game for himself is the center back role.”

Klinsmann isn’t making a big deal about the team’s lack of experience. Only five players among the 23 have appeared in a World Cup.

“The plan is to help them in that process, to get in that World Cup with a lot of confidence and being sure that they know what they’re doing. In every training session we will work on those pieces and we will guide them through all the different things that happen during a game, preparing the best way possible for the opponents they face in the group stage already,” Klinsmann said of the defense.

“I’m sure they’re going to be very well prepared and they will be ready for the task. There’s always a first time in life in whatever you do. It’s for some the first World Cup, though it’s the first of hopefully many World Cups to come for them. I’m not worried about the inexperience.”

NOTES: Landon Donovan, cut by Klinsmann on Thursday, broke the Major League Soccer goal record Sunday night. He returned to the LA Galaxy to score his 135th and 136th regular-season goals in a 4-1 victory over the Philadelphia Union.