U.S. Coach Jurgen Klinsmann announced his 23-man roster for two World Cup qualifiers and it was missing several regulars, including goalie Tim Howard and forward Landon Donovan. (J Pat Carter/AP)

At a pivotal stage of the World Cup qualifying campaign, the U.S. men’s national team will be without several regulars, including Tim Howard and Landon Donovan, for matches against Costa Rica and Mexico.

Some absences were not unexpected, but when Juergen Klinsmann’s 23-man roster was unveiled Monday, a number of probable starters who are either injured or not playing regularly with their European clubs were also scratched.

Howard, the first-choice goalkeeper for six years, is sidelined with a back injury sustained earlier this month playing for Everton in the English Premier League. Donovan, the U.S. team’s career scoring leader, has yet to resume workouts with the Los Angeles Galaxy since taking an extended break from soccer over the winter.

Also absent are captain Carlos Bocanegra, a central defender who has been sitting on the bench for Spanish club Racing Santander; injured outside backs Steve Cherundolo, Timothy Chandler, Fabian Johnson and Edgar Castillo; injured midfielder Jose Torres; and midfielder Daniel Williams, who has an undisclosed illness.

The Americans will play Costa Rica on Friday night at DSG Park near Denver and Mexico on March 26 at Azteca Stadium in Mexico City.

After dropping the first of its 10 final-round games, a 2-1 decision last month at Honduras, the United States needs to begin earning points to avoid falling too far behind in the six-team standings. Three nations will qualify for the 2014 World Cup in Brazil, while a fourth will advance to a playoff.

Both Costa Rica and Mexico settled for ties in their first games.

“We are not complaining about the situation,” Klinsmann said. “We take it the way it is. Do we wish we have those players back as soon as possible? Absolutely. But we feel comfortable with this roster and every guy to get the job done.”

The back line, which was vulnerable against Honduras, is particularly thin. With 34 U.S. appearances, Clarence Goodson (W.T. Woodson, University of Maryland) is the most experienced defender. Four call-ups have played in four or fewer international games.

Brad Guzan, a starter for English club Aston Villa, will replace Howard in net. Other regulars on the roster include Clint Dempsey, Michael Bradley, Jermaine Jones, Jozy Altidore, Herculez Gomez and Maurice Edu (Maryland).

D.C. United goalkeeper Bill Hamid and midfielder Chris Pontius were on Klinsmann’s preliminary list but didn’t make the final cut.

U.S.-Germany at RFK?

The U.S. Soccer Federation is close to announcing a U.S.-Germany friendly June 2 at RFK Stadium, multiple sources familiar with the negotiations said. FedEx Field had also been under consideration. Last week the USSF announced a May 29 friendly against Belgium in Cleveland. . . .

United extended the contract of defender Daniel Woolard, who was in the final year of his deal. Terms were not disclosed. Woolard, a left back, is in his third season with United. He started the opener at Houston but didn’t play the past two matches. . . .

Hamid was named MLS player of the week for a sterling performance during a 0-0 draw against the New York Red Bulls on Saturday. He made seven saves, including two spectacular stops on shots from close distance. . . .

Defender Dejan Jakovic (Canada) and midfielder Marcos Sanchez (Panama) reported for national team duty and will miss Saturday afternoon’s match against the Columbus Crew in Washington.