The Cubs sent Burdi outright to Triple-A Iowa on Thursday, Sahadev Sharma of The Athletic reports.
Burdi was selected from Triple-A in May, but he only made three appearances with the Cubs before appendicitis and a nerve issue in his right elbow put an early end to his season. Burdi holds a career 9.39 ERA through 15.1 innings and will likely need to prove he can remain healthy and effective before getting another shot in the majors.