Harang went on the DL on July 16 after being scratched from a start in New York because of back spasms. Reds manager Dusty Baker said he doesn't know when Harang will return or if he will need a rehab start.
"There's a chance. The longer he's out, the less sharp he's going to be endurance-wise, throwing-wise," Baker said. "We've got to get him back throwing on the mound first before we make that determination."
Prior to Thursday evening's workout, Baker said he still needed to talk to Harang, but the pitcher had still been feeling stiff.
Harang's last start came on June 30, when he allowed three runs in 6 1/3 innings in a 4-3 win against the Phillies.