Fisher will serve as the Blue Jays' opening pitcher for Wednesday's game in Boston, Arden Zwelling of Sportsnet.ca reports.
Max Scherzer had been scheduled to start Wednesday, but after he developed back spasms that resulted in his unexpected placement on the IL, the Blue Jays will pivot to a bullpen game. The opener assignment is a familiar one for Fisher, who has previously made four of his 36 appearances this season as a starter. He hasn't recorded more than six outs in any of those outings, so he'll likely cover no more than an inning or two before exiting the game. Chad Dallas and Simeon Woods Richardson are on hand as fresh arms capable of covering multiple frames in relief behind Fisher.