"Devin Mesoraco will have the opportunity to become a front-line catcher for us," Jocketty said. "Holmberg provides us with the quality pitching depth that every team needs."
Holmberg, 22, is ranked by MLB.com the fifth-best prospect and by Baseball America the sixth-best prospect in the Diamondbacks system. His control is rated the best among all Arizona minor leaguers.
In 2013, the Southern League All-Star threw at least 154 innings for the third straight season. He spent last season at Class AA Mobile, where in 26 starts he went 5-8 with a 2.75 ERA and 116 strikeouts over 157.1 innings. He made his major league debut and only appearance of the season for Arizona on August 27 against San Diego.
Originally selected by the White Sox in the second round of the 2009 first-year player draft, Holmberg was traded to Ariziona with RHP Daniel Hudson for RHP Edwin Jackson on July 30, 2010.
Hanigan, 33, last season for the Reds hit .198 in 75 games surrounding 2 stints on the disabled list. He caught both of Homer Bailey's no-hitters (9/28/12 at Pit, 7/2/13 vs SF).