Williams will be used as a bulk reliever in Sunday's game against the Astros, Mandy Bell of MLB.com reports.
All 16 of Williams' appearances with the Guardians to this point in the season have been traditional starts, but the club will try him as a primary reliever in his final regular-season outing, perhaps with an eye on using him similarly in the playoffs. For what it's worth, Williams has a 6.32 ERA in the first inning this season.