The move came before Friday night's game at Atlanta. Catcher Tomas Telis was optioned to Triple-A New Orleans.
Bour has hit .368 with 13 homers and 31 RBIs since April 30.
Prado, on the DL twice this season with a strained right hamstring, and Hechavarria, sidelined since May 9 with a strained left oblique, likely will spend several days on rehab assignments at Double-A Jacksonville. Both were set to play their first game Friday.