Jimenez (oblique) will begin a rehab assignment with Triple-A Las Vegas on Tuesday, Martin Gallegos of MLB.com reports.
Jimenez has been on the shelf since late June working his way back from a Grade 2 strain in his left oblique. He threw live batting practice Saturday without any issues and now figures to be just a handful of minor-league outings away from returning to Oakland's bullpen. However, the A's haven't specified how many appearances they want the 30-year-old to make with Las Vegas.