Diaz (biceps) will require at least two more throwing sessions before he's cleared to return, Charlie Goldsmith of The Cincinnati Enquirer reports.
The Reds initially hoped Diaz would be able to be reinstated from the injured list Friday, but he'll instead toss a bullpen Saturday prior to throwing a live BP on Monday. Once the right-hander is officially activated, it's possible he takes on a setup role since manager David Bell expressed confidence in Hunter Strickland as the Reds' closer last weekend.