The Seattle Mariners have designated right-hander D.J. Mitchell for assignment to clear space on their roster, reports Greg Johns of MLB.com:

The Mariners made it official on Wednesday, announcing the signing of free-agent outfielder Raul Ibanez to a one-year contract and designating right-handed pitcher D.J. Mitchell for assignment to make room on the 40-man roster.

Acquired from the New York Yankees as part of the Ichiro Suzuki trade in late July, the 25-year-old Mitchell received a very brief cup of coffee with the Bronx Bombers but never suited up at the big-league level for the M's. The right-hander posted a 4.29 ERA and 7.0 K/9 rate in 134⅓ innings across 22 starts overall at Triple-A in 2012, improving his numbers greatly once a part of the Seattle organization.

A 10th round pick out of Clemson University in 2008, Mitchell has spent the past three seasons knocking on the door of the major leagues, putting up a 3.68 ERA and 6.7 K/9 rate in 49 Triple-A starts.