Latest ticket sales figures for the U.S. men’s national team’s next four matches:

May 29 friendly vs. Belgium in Cleveland: 14,750

June 2 friendly vs. Germany in Washington: 33,000

June 11 World Cup qualifier vs. Panama in Seattle: 31,000

June 18 World Cup qualifier vs. Honduras in Sandy, Utah: 20,000 (sold out)

Capacity at RFK Stadium is 45,423, but organizers have suggested adding temporary seating behind the goals. Details have not been revealed yet. (D.C. United utilizes those areas for promotional and hospitality purposes.)

The Germany match is a big event — USA Coach Juergen Klinsmann facing his native country and former team, the U.S. Soccer Federation celebrating its centennial, the Americans at full strength playing an elite opponent in the build-up to two qualifiers.

But Germany, which begins the U.S. tour May 29 against Ecuador at Florida Atlantic University, will not have a full complement of regulars. Although the Bundesliga season ends May 18, Bayern Munich is active into June (UEFA Champions League final May 25 and German Cup final June 1) and Borussia Dortmund will face Bayern for the European title.

More than a dozen Bayern and Dortmund players are in the national team player pool.

Real Madrid’s Mesut Ozil and Sami Khedira are also unavailable because of La Liga commitments. Miroslav Klose, whose 67 goals are one shy of Gerd Mueller‘s record, seems unlikely as well because his Serie A club, Lazio, faces Roma in the Italian Cup final May 26.

USA UPDATE: Klinsmann says he will invite oft-injured midfielder Stuart Holden to training camp later this month. Holden has not appeared in a U.S. match since October 2010.

“We’ve been in touch with Stuart throughout this whole injury period,” Klinsmann said on the USSF’s website late today.  “The last couple of months have given us a lot of positive signals. I spoke to his coach at Bolton, and spoke to his coach at Sheffield Wednesday where he played some very important minutes and games while on loan. He’s on his way back. That being said, we want to have him back in our picture. We are going to bring him for the May-June camp, and also for the Gold Cup.”