A's acquire lefty De La Rosa from Arizona for cash
Oakland made the announcement Thursday, the latest trade in another offseason full of them for general manager Billy Beane.
De La Rosa, 24, began the 2014 season with Triple-A Reno and posted a 2.52 ERA in 36 relief appearances before being called up by Arizona July 5. He then went 2-0 with a 2.95 ERA in 25 games for the Diamondbacks. He allowed only two home runs in 36 2-3 innings.