A person familiar with the agreement tells The Associated Press that catcher Victor Martinez and the Detroit Tigers have reached a preliminary agreement on a $50 million, four-year contract.
The person spoke on condition of anonymity Tuesday because the deal, which is subject to a physical, had not yet been announced.
Martinez hit .302 with 27 homers in 127 games last season with Boston. He started 106 games at catcher and also can play first base. The Tigers might use him as a designated hitter. They've been looking for another big bat to go along with first baseman Miguel Cabrera.
Earlier this offseason, Detroit re-signed third baseman Brandon Inge and shortstop Jhonny Peralta and signed reliever Joaquin Benoit.
Cabrera turns 32 next month.
AP Sports Writer Ronald Blum contributed to this report.