Dunn (shoulder) is set to begin a rehab assignment Wednesday in the rookie-level Arizona Complex League.
Dunn is expected to return to the Reds as a reliever, but he's been out all season with a right rotator cuff injury and will need to prove his health and effectiveness with several minor-league rehab appearances. The 27-year-old struggled to a 6.10 ERA across 31 innings (seven starts) for Cincinnati in 2022.