"We're moving along and getting a little bit better," Arena told reporters on Saturday following a training session for Sunday's friendly against Latvia.

"It's the third game in five or six days," he said. "It tests the depths of your roster and tests your limits physically, so we just want to keep moving forward."

Arena arranged an 11-day training camp in the U.S. earlier this month and three friendlies against Morocco, Venezuela and Latvia to put his team on track for their Group E opener against the Czech Republic on June 12.

Despite fielding what many believed Arena's starting World Cup team against Morocco, the U.S. produced a thoroughly unimpressive performance and slumped to a 1-0 defeat to the North Africans on Tuesday.

Arena retained only two players for the Venezuela game and his reserves delivered a far more fluid display on Friday, running out 2-0 winners albeit against undoubtedly weaker opposition.

Arena has insisted the results of the friendlies had little relevance and that he was more concerned with what his team were doing rather than his opponents' capabilities.

"We've put very little time into these opponents, we really haven't concerned ourselves with them," he said.

"I can't even give you the name of one player. That's my fault, but it's not really that important to us right now."

GETTING COMFORTABLE

Having a fully fit squad available for the finals is another story, especially when it comes to determining a starting side.

"I don't think everything is really clear right now," Arena said. "It's been good to see our strikers, Brian Ching and Eddie Johnson, get a little more comfortable. Bobby Convey had a good game (against Venezuela) and Jimmy Conrad had a good game at centre back.

"I think it's a lot of the same guys who have impressed, but again, tomorrow's game, plus the training camp in Germany [Images] will tell us what we do on June 12."

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The U.S. also face Italy [Images] (June 17) and Ghana (June 22) in Group E.

Arena is eagerly awaiting the return to training of his two most talented midfielders, captain Claudio Reyna and John O'Brien, who are nursing minor hamstring injuries.

He is confident Reyna will be ready to train when the U.S. arrive in Hamburg on June 2 and he is hopeful O'Brien will also be deemed fully fit.

Arena is expected to field a mixture of likely starters with reserves against Latvia, including goalkeeper Kasey Keller, defenders Steve Cherundolo, Eddie Lewis and Eddie Pope, midfielders Landon Donovan, DaMarcus Beasley and Pablo Mastroeni and forwards Brian McBride and Josh Wolff.

"My goal is to start every game of the World Cup, not just to make the team," said PSV Eindhoven midfielder Beasley.

"I feel good, I feel 100 percent and I'm ready to play tomorrow (Sunday)."