10:18am: The deal is worth $39MM over three years, reports Jon Heyman of CBS Sports (via Twitter).
10:10am: The Red Sox have reached an agreement on a three-year contract with Mike Napoli, according to Nick Cafardo of the Boston Globe (via Twitter). WEEI.com's Rob Bradford was the first to report that the two sides were closing in on a deal.
Financial details of the deal aren't known yet, but Peter Abraham of the Boston Globe tweets that Boston likely paid a larger annual salary to get a three-year contract done, rather than going to four years for Napoli.
Napoli had a down year by his standards for the Rangers in 2012, hitting .227/.343/.469. However, he has a career .863 OPS, and is one season removed from a .320/.414/.631 line. While Boston likely doesn't expect him to produce at that level again, the team will make him its primary first base option, according to Bradford. Cafardo tweets that the 31-year-old will also catch occasionally for the Sox.