The Diamondbacks optioned Diaz to minor-league camp Thursday, Alex Weiner of ArizonaSports.com reports.
Diaz was touched up for four runs on three hits and two walks over 1.2 innings this spring. The righty shifted to a relief role at Triple-A Reno last season and will have to harness his control (73 walks in 57 minor-league innings in 2025) before the Diamondbacks consider him for their bullpen.