Fulmer was recalled from Triple-A Charlotte on Thursday, Daryl Van Schouwen of the Chicago Sun-Times reports.
He'll assume the active roster spot of starting pitcher Lucas Giolito (hamstring), who was placed on the 10-day injured list in a corresponding move. Though Giolito's move to the IL opens up a spot in the rotation, Fulmer won't necessarily be asked to fill the void. Fulmer came up through the system as a starter and made 13 turns with the White Sox between 2017 and 2018, but he transitioned to a relief role in spring training and has been used exclusively out of the bullpen in the majors and at Triple-A this season.