OAKLAND, Calif. (AP) The Oakland Athletics have designated left-hander Brad Mills for assignment to clear a roster spot for recently acquired pitcher Jason Hammel.

The A's also announced Monday that they have claimed outfielder Kenny Wilson off waivers from Toronto and optioned him to Triple-A Sacramento. In addition, Oakland outrighted outfielder Nick Buss to Sacramento and traded International Slot No. 57, worth $339,000, to Milwaukee for minor league pitcher Rodolfo Fernandez.

Mills went 1-1 with a 4.41 ERA in three starts for Oakland this season. But with Hammel scheduled to pitch Wednesday at San Francisco, the A's needed to clear space on the roster.

The A's got Hammel and right-hander Jeff Samardzija from the Cubs on Friday in a trade that sent three prospects to Chicago.

SI Apps
We've Got Apps Too
Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide - from Peter King, Tom Verducci, Lee Jenkins, Seth Davis, and more - delivered straight to you, along with up-to-the-minute news and live scores.