McMillon (forearm) is scheduled to make a relief appearance in Wednesday's Cactus League game against the Mariners, Anne Rogers of MLB.com reports.
McMillon will likely cover an inning Wednesday in what will mark his spring debut. The hard-throwing righty has been eased along during spring training while he works his way back from a forearm strain, but assuming he escapes Wednesday's outing free of setbacks, he should be on track to win a spot in the Royals' Opening Day bullpen. McMillon was impressive over a small sample of big-league action in 2023, striking out eight and allowing one earned run on one hit and no walks over four innings.