The Pirates activated Cruz on Sunday for their game against the San Diego Padres. He had been on the DL since July 18 with inflammation in his right shoulder.
Rookie right-hander Jared Hughes was optioned to Triple-A Indianapolis.
Cruz is 1-1 with three saves and a 2.61 ERA in 37 games. He pitched twice for Double-A Altoona on a rehab assignment and allowed two runs in 1 1/3 innings.
Hughes was 2-1 with one save and a 2.70 ERA in 47 relief appearances.