The Pirates acquired Yates from the Angels on Monday in exchange for right-hander Kyle Robinson, Ken Rosenthal of The Athletic reports.
Yates has logged a 3.95 ERA and 36:12 K:BB over 27.1 innings for the Halos this season. The 39-year-old will likely slot into a setup role as part of a retooled Pittsburgh bullpen. Yates will become a free agent after the season.