Difo's contract was selected from Triple-A Reno on Thursday.
Difo played in 116 games for the Pirates last season but was forced to settle for a minor-league role with the Diamondbacks to begin the 2022 campaign. He's slashed .269/.311/.398 with seven homers, 43 RBI, 33 runs and four stolen bases over 72 games at Reno this year but will provide depth for Arizona now that rosters have expanded to 28 players.