But Donovan, who this week signed a new contract with L.A. Galaxy, was recalled for July's CONCACAF Gold Cup and was the tournament's joint top scorer with five goals as the U.S. won the title.
He is by no means guaranteed a place in the starting lineup, however, given the established strike pairing of Jozy Altidore and Clint Dempsey and the inclusion of AZ Alkmaar striker Aron Johannsson, who recently switched allegiance to the United States after representing Iceland at Under-21 level.
Klinsmann has also used German-born wing-back Fabian Johnson on the left flank in recent games while Graham Zusi has been a solid presence on the right side of midfield.
The United States play Costa Rica in San Jose on September 6 and take on old rivals Mexico in Columbus, Ohio, four days later.
The U.S. head the six-team qualifying group with 13 points from six games ahead of Costa Rica on 11 and Mexico with eight.
The top three countries qualify for next year's World Cup finals in Brazil with the fourth-placed team going into a two-legged playoff against Oceania winners New Zealand.
The U.S. have never won a qualifier in Costa Rica but Klinsmann believes his squad can end that barren run.
"It's about going in there with confidence and winning, getting the three points. We have built that confidence over the last two years. We have built a roster now that is a lot deeper than it was before," he told ESPN's Sports Center.
"Just getting the results over the last two years, winning in Italy, beating Germany here... gives them now the confidence to say, 'Why not Costa Rica?' There is always a first time.
"We hope it's going to be the first time ever that we beat them on their soil in a World Cup qualifying game. There will be a lot of tension down there but I think we're ready for it."
One complicating factor for Klinsmann is that eight of his squad are one yellow card from suspension and if any of them are cautioned in Costa Rica they would miss the Mexico game.
SQUAD:
Goalkeepers: Brad Guzan (Aston Villa), Tim Howard (Everton), Nick Rimando (Real Salt Lake)
Defenders: DaMarcus Beasley (Puebla), Matt Besler (Sporting Kansas City) John Brooks (Hertha Berlin), Geoff Cameron (Stoke City), Edgar Castillo (Club Tijuana), Brad Evans (Seattle Sounders), Omar Gonzalez (LA Galaxy), Michael Orozco (Puebla)
Midfielders: Kyle Beckerman (Real Salt Lake), Alejandro Bedoya (Nantes), Michael Bradley (AS Roma), Mix Diskerud (Rosenborg), Fabian Johnson (Hoffenheim), Jermaine Jones (Schalke 04), Graham Zusi (Sporting Kansas City)
Forwards: Jozy Altidore (Sunderland), Clint Dempsey (Seattle Sounders), Landon Donovan (LA Galaxy), Aron Johannsson (AZ Alkmaar), Eddie Johnson (Seattle Sounders)
(Reporting by Simon Evans; editing by Ken Ferris)
