The Tigers outrighted Diaz to Triple-A Toledo on Friday, Chris McCosky of The Detroit News reports.
Diaz was scrubbed from the Tigers' 40-man roster earlier this week, but he's cleared waivers and will remain in the organization. The right-handed hurler has made four starts and nine relief appearances at the big-league level, collecting a 6.27 ERA and 26:20 K:BB across 37.1 frames.