Williams will start Sunday against the Reds after his scheduled start Saturday was rained out, Bill Brink of the Pittsburgh Post-Gazette reports.
Chris Archer and Jameson Taillon will remain on schedule for next week's series against the Cardinals, with Joe Musgrove getting bumped Sunday in favor of Williams. That doesn't necessarily mean that Williams is viewed as ahead of Musgrove, however, as Musgrove's start to spring had been delayed due to recovery from abdominal surgery, so it's likely that the team was happy to give him a few extra days to build up.