Williamson (shoulder) struck out two and allowed one earned run on five hits and no walks across 3.2 innings in a rehab appearance Sunday with Triple-A Louisville.
Taking the hill for the fourth start of his rehab assignment, Williamson built up to 63 pitches (47 strikes) and induced seven whiffs while averaging 92.7 mph with his four-seam fastball. The Reds will likely decide on Williamson's next step within the next couple of days, but the left-shoulder shouldn't need more than one more tune-up outing in the minors before returning from the 60-day injured list. With Rhett Lowder performing well over the past month as the Reds' No. 5 starter, Williamson may not have a path to the rotation once he's activated and could have to settle for a long-relief role.