The Padres added Workman to the 26-man active roster ahead of Tuesday's game against the Diamondbacks.
Workman had been playing at Triple-A Toledo since the beginning of June, but he'll open his time in the Padres organization with the big club after he was acquired from the Tigers on Monday. The 26-year-old has seen time at second base, third base, shortstop and both corner-outfield spots between his stops in the majors and minors this season, so he'll offer the Padres some versatility off the bench.