In return for Ackley, the Mariners received outfielder Ramon Flores and pitcher Jose Ramirez.
Ackley, once a top prospect after being drafted second overall by Seattle in 2009, has failed to live up to hefty expectations since being brought up to the Major Leagues, being a slightly above league-average player prior to this season.
The Yankees have had awful performances from their second basemen and hope that with a change of scenery Ackley can be their man. Yankees' second basemen have produced the fewest fWAR in the entire Major Leagues, being well below average both offensively and defensively.
Ackley, 27, is far from a guarantee production-wise, posting a career-worst .215/.270/.366/.635 line this season with six homers and 19 RBIs over 207 plate appearances.
Perhaps a silver lining in the Ackley acquisition is that he has a career .296/.397/.481 line with two homers and nine RBIs in 17 career games at Yankee Stadium.
The University of North Carolina alumni is signed through the 2017 season.