Strop (hamstring) will begin a rehab assignment with Triple-A Iowa on Tuesday, Mark Gonzales of the Chicago Tribune reports.
It was unclear whether Strop would need a rehab assignment before returning to the Cubs. However, given his three-week absence, the team has opted for him to complete a few warmup outings. Assuming there are no setbacks in his recovery, he should be activated from the injured list after making two appearances for Iowa, one on Tuesday night and another Thursday.