Klinsmann's men are taking on Mexico at the University of Phoenix Stadium on April 2 as they step up their preparations for the global showpiece.
With the exception of uncapped Bayern Munich forward Julian Green, who has been given permission to feature by the recently-crowned Bundesliga champions, the US' European-based players are unavailable.
Klinsmann has, therefore, urged those selected to seize their opportunity and make a lasting impression.
"Everyone knows the clock is ticking," he told US Soccer's official website. "This is a huge opportunity for our players to show where they are at and to make their case.
"We expect them to give a really strong performance against a Mexican team that is now basically coming back on track. They need to prove now that they badly want to go to Brazil."
Full squad:
Goalkeepers: Bill Hamid (D.C. United), Sean Johnson (Chicago Fire), Nick Rimando (Real Salt Lake)
Defenders: DaMarcus Beasley (Puebla), Matt Besler (Sporting Kansas City), Brad Evans (Seattle Sounders FC), Omar Gonzalez (LA Galaxy), Clarence Goodson (San Jose Earthquakes), Michael Orozco (Puebla), Michael Parkhurst (Columbus Crew), DeAndre Yedlin (Seattle Sounders FC)
Midfielders: Kyle Beckerman (Real Salt Lake), Michael Bradley (Toronto FC), Brad Davis (Houston Dynamo), Landon Donovan (LA Galaxy), Maurice Edu (Philadelphia Union), Luis Gil (Real Salt Lake), Graham Zusi (Sporting Kansas City)
Forwards: Clint Dempsey (Seattle Sounders FC), Julian Green (Bayern Munich), Eddie Johnson (D.C. United), Chris Wondolowski (San Jose Earthquakes)
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