According to MLB.com, Reds manager David Bell told reporters an MRI showed a stress reaction, or a reoccurence of the original injury. Lodolo will seek a second opinion.
“Obviously, it’s concerning news, but I don’t have anything beyond that,” Bell said.
Lodolo made his first rehab start for Louisville on Aug. 11 and pitched again Aug. 15. He allowed two earned runs on three hits in 2 1/3 innings Sunday.
The Reds started a 10-game road trip with a 4-3 victory against the Los Angeles Angels in Anaheim, Calif. They play a doubleheader Wednesday.
The Reds are four games out of first place in the National League Central Division and a half game back of the last wild-card spot.