Contreras was recalled by the Pirates on Friday, Jason Mackey of the Pittsburgh Post-Gazette reports.
Contreras is one of the Pirates' top pitching prospects. He was called up for a single three-inning start last September but otherwise has only made one other start above Double-A. He was optioned to Triple-A Indianapolis in late March but will be back for another opportunity already. Exactly what his role will be is unclear. Reliever Duane Underwood (hamstring) was placed on the injured list in a corresponding move. Contreras could work out of the bullpen in his place or enter the rotation and push a different pitcher to that role.