Rocker will work as the bulk reliever behind opener Trevor Williams for Friday's game against the Rays, Jeff Wilson of AllDLLS.com reports.
Rocker has appeared in 26 games this season, 24 of which have been as a traditional starter. He's followed an opener twice and has experienced success with it, going a season-high 7.2 innings at Coors Field back in May before covering five innings in Miami in June. In total, the right-hander has allowed just two runs on eight hits and three walks with 15 strikeouts across those 12.2 frames.