Strop, who has been on the disabled list since Aug. 11, tweaked his right groin on Wednesday and his rehab will be slowed down. When he was initially injured, the prognosis was that it would take the right-hander four to six weeks, and it now looks as if the six-week timeline is more accurate.
The Cubs did get good news regarding reliever Hector Rondon, who has been out since Aug. 17 with a right triceps strain. Rondon will begin a rehab assignment with Triple-A Iowa and was scheduled to pitch Saturday and Monday.
• Chris Coghlan (right rib contusion) was activated from the disabled list along with right-handed pitcher Joe Smith (left hamstring strain), and the Cubs also selected the contract of right-hander Jake Buchanan from Iowa.