Among the players called up is defender Ali Krieger, who started for Germany's FFC Frankfurt in its 1-1 tie with Swedish champion Umea Saturday in the first leg of the UEFA Women's Cup.
Krieger, who earned her first two caps for the USA in January at the Four Nations Tournament in China, will join the camp after next Saturday's second leg at the former Waldstadion in Frankfurt.
Defender Keeley Dowling and midfielder Angie Woznuk return to camp after missing action while recovering from back injuries.
Sundhage has called in 2004 Olympic gold medalist Kristin Luckenbill to join Hope Solo and Briana Scurry in the U.S. net.
Sundhage has also called in one player who has yet to see training camp action, giving a look to uncapped defender Kendall Fletcher, a former North Carolina star.
Two players currently recovering from minor surgery - goalkeeper Nicole Barnhart (knee) and captain Christie Rampone (gall bladder) - will join the camp if they are fit enough to participate.
Sundhage will choose a 20-player roster to compete in the Peace Queen Cup, where the Americans will play Australia (June 15), Brazil (June 17) and Italy (June 19). If the USA wins the group, it will play for the Peace Queen Cup title on June 21.
After the South Korea trip, the USA has four games scheduled -- two in Europe against Norway and Sweden and two at home against Brazil -- before heading to the Beijing Olympics.
U.S. Training Camp Roster
GOALKEEPERS: Kristin Luckenbill (Paoli, Pa.), Briana Scurry (Dayton, Minn.), Hope Solo (Richland, Wash.);
DEFENDERS: Rachel Buehler (Del Mar, Calif.), Lori Chalupny (St. Louis, Mo.), Stephanie Cox (Elk Grove, Calif.), Keeley Dowling (Carmel, Ind.), Kendall Fletcher (Cary, N.C.), Ali Krieger (Dumfries, Va.), Kate Markgraf (Bloomfield Hills, Mich.), Heather Mitts (Cincinnati, Ohio), Cat Whitehill (Birmingham, Ala.);
MIDFIELDERS: Shannon Boxx (Redondo Beach, Calif.), Tobin Heath (Basking Ridge, N.J.), Angela Hucles (Virginia Beach, Va.), Carli Lloyd (Delran, N.J.), Leslie Osborne (Brookfield, Wis.), Lindsay Tarpley (Kalamazoo, Mich.), Aly Wagner (San Jose, Calif.), Kacey White (Arlington, Texas), Angie Woznuk (El Cajon, Calif.);
FORWARDS: Lauren Cheney (Indianapolis, Ind.), Natasha Kai (Kahuku, Hawaii), Heather O'Reilly (East Brunswick, N.J.), Amy Rodriguez (Lake Forest, Calif.), India Trotter (Plantation, Fla.), Abby Wambach (Rochester, N.Y.)