Diaz (hamstring) allowed one unearned run on one hit and one walk while striking out one over one inning for Triple-A Louisville on Sunday.
It was rehab day for Louisville, which featured starter Andrew Abbott (shoulder) making his second rehab start and Diaz's second rehab outing. The reliever has already healed from a left hamstring strain, per Mark Sheldon of MLB.com, but he might get another rehab appearance before the Reds activate him. Diaz is not guaranteed to resume his duties as Cincinnati's closer.