Diaz will move up from Double-A to Triple-A to continue his rehab assignment, Pirates Prospects reports.
GM Neal Huntington said Sunday that Diaz would head to Triple-A as soon as fellow rehabbing catcher, Francisco Cervellli, was ready to return in Pittsburgh. Unless Cervelli suffers an injury Sunday then he'll likely be back Tuesday with the Pirates following Monday's day off. Huntington said he's gotten good reports on Diaz, who's gone 11-for-30 in Altoona.