The Mariners have designated 25-year old righty starter/reliever D.J. Mitchell for assignment. Mitchell pitched in 4 games (0 starts) for the Yankees last year in his first taste of the majors and he was 0-0 with a 3.86 ERA and a 2.14 WHIP. He also pitched in 23 games (22 starts) for the Mariners and Yankees in AAA-ball last year in which he was 9-6 with a 4.29 ERA and a 1.30 WHIP. Mitchell was part of the return the Mariners got for Ichiro Suzuki when they dealt him to the Yankees.
UPDATE: (1/5/2012) - D.J. Mitchell has accepted an outright assignment to AAA, so he will remain with the Mariners.