The week-long camp will be Nowak's final chance to train and evaluate players before selecting the team that will compete in CONCACAF Men's Olympic qualification tournament March 11-23, 2008, in Los Angeles, Tampa and Nashville.
The USA will play three games of the group stage in Tampa against Cuba on March 11, Panama on March 13 and Honduras on March 15.
The eight-team tournament will send the two finalists to the 2008 Olympic Games in Beijing.
Thirteen of the players called in were part of the Under-23s latest camp from Jan. 6-20, and will be returning to Bradenton after a two-week break.
Included in the roster is Michael Orozco, who plays for San Luis in Mexico He is one of four players who play professionally outside of Major League Soccer, along with Charlie Davies of Hammarby IF (Sweden), Tally Hall of Esbjerg fB (Denmark) and Kamani Hill of VfL Wolfsburg's (Germany).
U.S. U-23 ROSTER
Dominic Cervi (Chicago Fire), Tally Hall (Esbjerg fB), Chris Seitz (Real Salt Lake)
Kamani Hill (Vfl Wolfsburg), Patrick Ianni (Houston Dynamo), Chance Myers (Kansas City Wizards), Michael Orozco (San Luis), Mike Randolph (LA Galaxy), Nathan Sturgis (Real Salt Lake), Anthony Wallace (FC Dallas), Marvell Wynne (Toronto FC).
Arturo Alvarez (FC Dallas), Maurice Edu (Toronto FC), Eddie Gaven (Columbus Crew), Stuart Holden (Houston Dynamo), Sacha Kljestan (Chivas USA), Dax McCarty (FC Dallas)
FORWARDS (6): Josmer Altidore (New York Red Bulls), Chad Barrett (Chicago Fire), Adam Cristman (New England Revolution), Charlie Davies (Hammarby IF), Robbie Findley (LA Galaxy), Robbie Rogers (Columbus Crew)