Seattle made the move official Wednesday after clearing a spot on its 40-man roster by designating for assignment right-handed pitcher D.J. Mitchell, who was acquired from the New York Yankees in the trade last July for Ichiro Suzuki.
The deal allows Ibanez to earn an additional $1.25 million in performance bonuses. This will be his third stint with the Mariners, after rejoining them from 2004-08.
Seattle general manager Jack Zduriencik says the team wanted to add veteran leadership in the offseason, and Ibanez provides that. The 40-year-old Ibanez hit .240 with 19 homers and 62 RBIs in 384 at-bats for the Yankees last season.