Bynum hit .192 with five RBI in 34 games. The Orioles have 10 days to trade, release or send him outright to the minors.
Baltimore selected the contract of right-hander Ryan Bukvich from Triple-A Norfolk to take Bynum's roster spot. Trembley said he wanted another option in the bullpen after starter Radhames Liz lasted only two-plus innings in an 8-5 victory over Milwaukee on Friday night.
Cintron was batting .325 with one homer and four RBI. Luis Hernandez was the starting shortstop to begin the season, but was outrighted to Norfolk earlier this month after batting .241 in 36 games.