Maples (finger) began a rehab assignment at Triple-A Iowa on Aug. 11 and has made four appearances, covering 4.1 innings while giving up four runs on five hits and four walks while striking out seven.

Before going on the injured list July 29 with a blister on his right middle finger, Maples was a productive reliever for Chicago with a 2.28 ERA and 1.12 WHIP in 24 appearances, but he hadn't yet moved into a high-leverage role. With that in mind, the Cubs may want to see Maples turn in better results during his rehab assignment before bringing him back from the IL.