Hentges (shoulder) is scheduled to begin a rehab assignment with Triple-A Columbus on Tuesday, Chris Assenheimer of the Elyria Chronicle-Telegram reports.
Hentges will throw in a game for the first time since being placed on the 15-day injured list July 12 with shoulder inflammation. It's unclear how many rehab outings Hentges will need before rejoining the Guardians bullpen, but he should be expected back sometime in mid-August.