Dunn's rehab assignment at Triple-A Louisville was halted Thursday after he suffered a setback with his right shoulder, MLB.com reports.
Dunn's last two seasons have been torpedoed by shoulder problems, with a subscapularis muscle in his right rotator cuff having kept him on the Reds' injured list since spring training. He began a rehab assignment in the rookie-level Arizona Complex League on Aug. 16 and made two appearances for the affiliate before moving on to Louisville, but he made just one appearance at the Triple-A level before being shut down again. The Reds haven't provided word on the severity of his setback, but Dunn could be hard-pressed to make it back from the IL before the end of the 2023 campaign.