The Diamondbacks reassigned Campbell to minor-league camp Thursday, Alex D'Agostino of SI.com reports.
Plenty of spots in Arizona's Opening Day bullpen were up for grabs in spring training, but Campbell was unable to seize one despite allowing just two baserunners over five innings across six Cactus League appearances. Campbell saw big-league action in each of the past three seasons but is slated to begin the 2026 campaign at Triple-A Reno.