Brentz (elbow) will report to Double-A Northwest Arkansas on Sunday to begin a rehab assignment.
Brentz has been sidelined by a flexor strain in his left elbow since late April, but he's entering the final stage of his rehab program. The 27-year-old surrendered 14 earned runs with a 9:10 K:BB across 5.1 innings prior to landing on the injured list.