Ober (groin) will begin a rehab assignment at Triple-A St. Paul on Saturday, Do-Hyoung Park of MLB.com reports.
Ober threw 20 pitches during a bullpen session Wednesday and will now return to game action with the team's Triple-A affiliate. If the right-hander's Triple-A start goes well Saturday, he'll likely be in the mix to rejoin the Twins' rotation late next week or sometime next weekend.