Miller (elbow) threw off flat ground Saturday from approximately 60 feet, the Associated Press reports.
Miller had been shut down for about five weeks with right elbow inflammation before the Diamondbacks cleared him to resume a throwing program. It's expected that the team will proceed cautiously in moving Miller through his rehab, given that he's just over 15 months removed from undergoing Tommy John surgery. Miller had made four starts for the big club before hitting the 60-day disabled list, but it's expected he'll return in a bullpen role if the Diamondbacks choose to activate him before the regular season draws to a close.