Heuer (elbow) is scheduled for a third minor-league rehab appearance Friday with Triple-A Iowa, Meghan Montemurro of the Chicago Tribune reports.
Heuer struggled in his rehab debut Saturday with Iowa before striking out two of three batters he faced in his second rehab outing Tuesday. The 26-year-old reliever is on the long road back from Tommy John surgery and should be an option for the Cubs' bullpen at the end of this month. He's on the 60-day IL and isn't eligible for activation until May 29.