Dunn (shoulder) will make his fifth rehab start at Triple-A Louisville on Sunday, Bobby Nightengale of The Cincinnati Enquirer reports.
Dunn built up to 74 pitches during Tuesday's rehab start at Louisville, and he's expected to throw approximately 85 pitches Sunday. While the right-hander has made good progress in recent weeks, he's expected to require another rehab start after the All-Star break prior to returning from the injured list.