Contreras will start Tuesday at home against the Rockies, Alex Stumpf of DKPittsburghSports.com reports.
The Pirates haven't officially confirmed their starter for Tuesday's game, but they have a gap in the rotation and Contreras was just recalled Sunday, so it seems clear that the job is his. In 10.2 career major-league innings, Contreras owns a 2.53 ERA, striking out 14 batters while walking just four. He recorded a 2.66 ERA and a 28.9 percent strikeout rate in five starts for Triple-A Indianapolis prior to his promotion.