The Red Sox officially announced the signing of Mike Napoli to a two-year contract. The first baseman agreed to terms last week on a $32 million deal. The contract calls for $16 million a season with limited no-trade rights.
To make room on the 40-man roster, the Red Sox designated utility player Alex Castellanos for assignment.
The Red Sox obtained Castellanos from the Dodgers on Oct. 23 for Jeremy Hazelbaker.