The deal is expected to be announced Friday afternoon.
Gonzalez receives a $6 million signing bonus, $21 million per year from 2012-16 and $21.5 million per year in 2017 and 2018, sources with knowledge of the deal told ESPN The Magazine's Buster Olney. Sources also said the deal has a partial no-trade clause.
Not particularly shocking, as this deal was in the works even before Gonzalez was officially acquired by Boston in the offseason.
By doing this, the Red Sox secure a first baseman who has been a 3+ WAR player every year since 2006, despite playing in a notorious pitchers park in San Diego. Gonzalez turns 29 in May, so the Sox have essentially overpaid on the back end to ensure elite level service for most of his peak years (generally, ages 28-32).
Despite the slow start to the season in the slugging department, Gonzalez projects to be a .280/.380/.500 type player for the next several seasons while also providing elite level defense in the field.
Fenway is generally regarded as a very good hitters park, especially for right handed sluggers, although research shows it it doesn't enhance home runs like it does doubles or triples.
That being said, Gonzalez's ability to use the entire field will play anywhere, even in the home run department, which was made more than evident by his success at Petco Park (where home runs go to die).
Overall, the deal seems perfectly reasonable for the time being, but chances are the Sox won't enjoy paying $21.5 million those last two years when Gonzalez will be 35+ years old, a time when power hitters are generally declining.