MLB: A's place Robertson on DL

Baltimore, MD (Sports Network) - The Oakland Athletics placed pitcher Connor Robertson on the 15-day disabled list Friday with a fractured right thumb. The move is retroactive to Tuesday.
Robertson was selected from Triple-A Sacramento on May 15 and posted an 18.00 ERA in three games for Oakland. He suffered the injury in Monday's game at Chicago.
To take his spot on the roster, the A's selected pitcher Erasmo Ramirez from Sacramento. Ramirez was 3-0 with a 1.27 ERA and two saves in 19 relief appearances for Sacramento. Oakland cleared a spot for him on the 40-man roster by designating pitcher David Shafer for assignment.
Oakland also announced that catcher Jeremy Brown has cleared waivers and has been outrighted to Sacramento.