The veteran hurler was in Spring Training this year with the Yankees, but was designated for assignment on March 29.
Aardsma last appeared in the Majors with the Yankees in 2012, when he pitched in one game and allowed a run in one inning. He saved a combined 69 games for the Mariners over the 2009 and '10 seasons, then had elbow ligament replacement surgery in July 2011.
Aardsma is 13-15 with a 4.22 ERA in 255 games (266 2/3 innings).
Joey Nowak is a reporter for MLB.com. Follow him on Twitter at @joeynowak.& This story was not subject to the approval of Major League Baseball or its clubs.