Williamson (shoulder) struck out two over four scoreless innings in his rehab start Sunday with Triple-A Louisville. He gave up one hit and no walks in the 49-pitch outing.
Williamson made the fourth start of his rehab assignment Sunday and his third in a row with Louisville. The Reds have been having Williamson build up slowly as he works his way back from a left shoulder strain, which he suffered in a Cactus League game in mid-March. Williamson is eligible to return from the 60-day injured list whenever the Reds deem him ready to go, but he'll likely need to build his pitch count up to around 75 before he's available to handle a typical starter's workload. The Reds don't appear to have a spot in the rotation available for Williamson at the moment, so he could be optioned to Louisville once he's activated if the team's current five starters are all still healthy.