Pruitt is scheduled to serve as Oakland's opening pitcher for Wednesday's game against the Tigers, Martin Gallegos of MLB.com reports.
Pruitt hasn't tossed more than three innings or 35 pitches in any of his 32 appearances between the majors and minors this season, so the Athletics likely won't ask him to work more than once through the order before he turns the game over to the bullpen. Lefty Ken Waldichuk is expected to work in bulk relief behind Pruitt.