Fulmer, who was demoted to Triple-A Charlotte following Friday's game, will work on a mechanical issue, Tom Musick of the Chicago Sun-Times reports.
Fulmer has been kicking side to side in his delivery instead of straight up and down. "We're trying to clean that up so it's a more direct line," manager Rick Renteria said. "Those are things that he's been trying to work on. That, and with the weight of trying to help win a major-league ballgame on a daily basis, you compound it. Now, instead of bogging him down, we're going to try to alleviate a little bit of that stress." Fulmer will join Charlotte's starting rotation, and the White Sox do not plan to move him to the bullpen.