Martinez, a member of the Yankees in 1996-2001, played on four World Series champion squads (1996, 1998, 1999 and 2000) in six seasons and drove in at least 100 runs five times after being acquired from Seattle following the 1995 season. He left the Yankees after the 2001 season.

In 2004, the 37-year-old Martinez hit .262 with 23 homers and 76 RBI in 138 games for the Tampa Bay Devil Rays after playing the prior two seasons for St. Louis.

He has a career average of .272 with 322 homers and 1,222 RBI in 1,892 games. He has been an All-Star twice in his 15-year career. He likely will share time at first base and designated hitter with Jason Giambi.

Martinez is just the second position player signed by the Yankees this winter, joining second baseman Tony Womack.