Diaz has been reinstated from the 60-day disabled list and optioned to Triple-A Indianapolis.
During the final 10 games of his rehab assignment, Diaz hit .324 with only four strikeouts in 34 at-bats. He hasn't exactly provided stellar production across the board in his eight years in the minors, but the Pirates may call on Diaz at some point in the second half to spell Francisco Cervelli occasionally behind the plate.