Prior to the naming of the squad by Brazil's Argentine coach Ruben Magnano on Thursday, there had been doubt as to whether Barbosa, a guard with the Indiana Pacers, and Nene, a forward with the Washington Wizards, would be included.
But Magnano, who steered his own country to the gold medal at the Athens Games in 2004, told Reuters in an interview last week that Brazil could not afford to "close doors" and would take the strongest team possible to London.
The pair missed last year's Americas qualifying tournament where Brazil booked their ticket for London, the country's first appearance at the Games in 16 years.
NBA centers Anderson Varejao of the Cleveland Cavaliers and Tiago Splitter of the San Antonio Spurs were also named to the list of 15 that will be cut to 12 for the July 27-Aug. 12 Games.
Also included was U.S.-born guard Larry Taylor, who recently obtained Brazilian nationality.
The squad will assemble on June 10 to prepare for the Games where they have been drawn in Group B with 2008 Olympic silver medallists Spain, hosts Britain, Australia and China.
