U.S. men’s national soccer team Coach Juergen Klinsmann watches warm-ups at Stanford University as preparations begin in earnest for June’s World Cup in Brazil. (Tony Avelar/Associated Press)

They have begun arriving from England, France and Austria, from Mexico, Houston and 15 miles up the 101 from San Jose. The meeting point is Stanford’s athletic complex for the start of World Cup training camp — 30 players seeking 23 seats on a charter to Brazil on June 8.

“This is building the foundation for hopefully a successful World Cup,” Coach Juergen Klinsmann said Wednesday before the first session. “It’s a lot of work, it’s doing our homework, it’s fine-tuning a lot of elements, it’s tactical, it’s technical, and it’s making this team as strong as possible.”

In preparation for the most daunting first-round group — Germany, Portugal and Ghana await — the Americans will work for nearly two weeks in the Bay Area, culminating with a May 27 friendly against Azerbaijan at Candlestick Park in San Francisco. They will then move to New Jersey and a June 1 tuneup against Turkey at Red Bull Arena and finally a send-off against Nigeria six days later in Jacksonville, Fla.

“These next couple weeks are going to be pretty taxing physically and mentally,” said Houston Dynamo midfielder Brad Davis, one of several candidates on the roster bubble. “The staff wants to see who will push it to the limits to make this group. We don’t have a lot of time to prove they want to be on that plane.”

Klinsmann’s aim is two-fold: narrow his squad while conditioning his crew for the sport’s ultimate competition. He initially planned to invite 26 to 28 players, but settled on 30 because “we’re not sure yet. We want to see them come in and compete for the spots. We have 50-50 spots all over the place.”

Most slots are, in essence, already filled. Veterans such as Tim Howard, Clint Dempsey, Michael Bradley and several others are focused on their form, not their roster status. The same goes for players who have been part of Klinsmann’s camps for most of three years, regulars like Geoff Cameron, Graham Zusi and Matt Besler.

For others, the large number of invitees has raised the competitive spirit.

“We’re all friends, but we’re competing for a spot on the team,” said defender-midfielder DaMarcus Beasley, who made his World Cup debut at age 20 in 2002. “No one is guaranteed a spot. Playing against your roommate is difficult but at the same time, we all have one goal and hopefully we share it on the field.”

The players with the most to prove: defenders Timothy Chandler, DeAndre Yedlin and John Brooks, midfielders Davis, Julian Green, Joe Corona and Maurice Edu, and forwards Chris Wondolowski and Terrence Boyd.

The U.S. Soccer Federation had suggested final cuts would come by the end of May, but Klinsmann said he might wait until the FIFA deadline June 2.

Not every camper reported Wednesday. Bradley, Besler and Zusi are completing MLS obligations and forward Aron Johannsson and midfielder Jermaine Jones have yet to complete their respective European seasons.

Cameron, Howard and second-choice goalkeeper Brad Guzan were given time off after finishing Premier League campaigns Sunday. Their English-based colleague, forward Jozy Altidore, did report right away; Altidore played infrequently with Sunderland the second half of the season and needs the work.

Dempsey, the captain, will arrive Thursday from Seattle. Defender Omar Gonzalez is recovering from a knee injury suffered with the Los Angeles Galaxy and should be ready by the end of the week, Klinsmann said. Edu’s activity was limited because of concussion symptoms suffered in Philadelphia’s match last weekend.

Emphasizing the importance of building fitness and form, Klinsmann said many players from Portugal, Germany and Ghana are well ahead of his squad after completing 10-month campaigns with European clubs. Conversely, half of the U.S. roster is employed in MLS, which is barely one-third through the season.

“Every day we have at our disposal is really important to us because a lot of our guys don’t have the same foundation as our opponents,” he said. “We have to be clear about that. They have X amount of games in their legs. Hopefully we can catch up and maybe get a little bit more on top of it. It starts today.”

U.S. notes: Asked about Brazil’s stadium and infrastructure delays, Klinsmann said he does not anticipate major problems for the 32 teams.

However, he said, “It’s not going to be a perfect World Cup. . . . It’s going to be an extreme type of a World Cup. You have got to be prepared you are not going to get everything on a nice table. . . . There will definitely be issues in certain things. I call it a World Cup of patience.”