The Jayhawks were chosen to represent the country, but have the option to add other players. It became necessary when point guard Devonte' Graham partially tore a tendon in his left knee.
Graham is expected to be sidelined for about three weeks.
DeBose was chosen in part because he is coached at Florida Gulf Coast by Joe Dooley, a longtime Kansas assistant. That means DeBose is already familiar with the Jayhawks' system.
The U.S. team plays Canada in a pair of exhibitions next week. It leaves for South Korea on June 28, with competition beginning July 3.