To make room for Korecky on the 40-man roster, the D-backs designated right-hander Jailen Peguero for assignment.
Korecky, 29, appeared in 16 games for the Twins last year, going 2-0 with a 4.58 ERA. The right-hander spent the majority of the year with Triple-A Rochester, going 6-5 with a 2.91 ERA in 53 games.
"We've liked him," D-backs general manager Josh Byrnes said. "He's a good strike thrower, he has a pretty good slider."
The D-backs essentially have four spots set in their bullpen -- closer Chad Qualls, Tony Pena, Jon Rauch and Scott Schoeneweis. One of the remaining spots would likely go to a pitcher who could give them some innings in long relief -- like a Yusmeiro Petit or Billy Buckner -- while another could go to recently signed Tom Gordon if he is healthy enough begin the season.
That leaves at least one spot and maybe as many as three still open, and Korecky will compete for one.
"There's some murkiness related to two or three spots in our bullpen and we feel like he's certainly a competitor for one of those spots," Byrnes said.
Peguero was likely placed on waivers on Wednesday, though the club is prohibited from confirming that, and if he clears by Friday, he would return to camp as a non-roster player. Until that time, he is not allowed on the practice field.
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.