The Pirates activated Yates (shoulder) from the 15-day injured list Tuesday.
Yates has not pitched at all in September due to a right shoulder impingment. He did not go out on a rehab assignment, as the Pirates were satisfied with the work Yates did on the side to show he was ready for reinstatement. The veteran reliever posted a 2.19 ERA and 11:5 K:BB over 12.1 innings in August after the Pirates acquired him at the trade deadline.