The MLS trio is Landon Donovan, Ricardo Clark and Brian Ching.
The foreign-based players include Cory Gibbs. Because of a knee injury, the Charlton Athletic defender has been unavailable since Bradley took charge of the team in December of 2006.
Also in the squad is midfielder Benny Feilhaber, who had been left out of the U-23 squad for Olympic qualifying and hasn't seen action for his EPL club Derby since Jan. 2.
Three of Fulham's U.S. contingent -- Carlos Bocanegra, Clint Dempsey and Eddie Johnson - are in the squad.
"This is an excellent opportunity to gather a majority of our European-based players and continue to make evaluations prior to the start of World Cup qualifying," said Bradley.
The game on Wednesday in Poland (3:30 pm ET on Fox Soccer Channel) is the first of three friendlies the USA will play in Europe in its buildup to 2010 World Cup qualifying this summer, when it meets the winner Barbados and Dominica in a two-game series in June.
The USA faces England on May 28 and Spain June 4.
U.S. ROSTER for March 26 Poland game
Marcus Hahnemann (Reading/England), Tim Howard (Everton/England).
Carlos Bocanegra (Fulham/England), Steve Cherundolo (Hannover 96/Germany), Jay DeMerit (Watford/England), Cory Gibbs (Charlton Athletic/England), Oguchi Onyewu (Standard Liege/Belgium), Heath Pearce (Hansa Rostock/Germany), Jonathan Spector (West Ham//England)
Michael Bradley (Heerenveen/Netherland), Ricardo Clark (Houston Dynamo), Landon Donovan (Los Angeles Galaxy), Benny Feilhaber (Derby County/England), Eddie Lewis (Derby/England).
Brian Ching (Houston Dynamo), Clint Dempsey (Fulham/England), Eddie Johnson (Fulham/England), Josh Wolff (1860 Munich/Germany).