Victor Martinez is joining the Detroit Tigers, bringing another powerful bat to a lineup that already includes slugger Miguel Cabrera.

Martinez and the Tigers reached a preliminary agreement on a $50 million, four-year contract, a person familiar with the agreement told The Associated Press on Tuesday. The person spoke on condition of anonymity because the deal, which was subject to a physical, had not yet been announced.

In 127 games this year with Boston, Martinez hit .302 with 20 homers and 79 RBIs. Although he started 106 games at catcher and also can play first base, the Tigers might use him as a designated hitter.

Detroit already re-signed third baseman Brandon Inge and shortstop Jhonny Peralta this offseason, and the Tigers added reliever Joaquin Benoit last week. They were looking for another big bat to go along with Cabrera, who hit .328 with 38 home runs in 2010 and finished second to Josh Hamilton in the AL MVP vote.

Despite Cabrera's efforts, the Tigers finished only eighth in the American League in runs. They were hurt by injuries to Inge, Magglio Ordonez and Carlos Guillen.

Ordonez is recovering from right ankle surgery and played only 84 games. The Tigers did not exercise his $15 million option, so he's a free agent. Detroit announced Tuesday it would not offer arbitration to Ordonez.The Tigers also declined arbitration to outfielder Johnny Damon, catcher Gerald Laird and pitchers Jeremy Bonderman and Bobby Seay.

General manager Dave Dombrowski, who declines comment until agreements are finalized, has left open the possibility Ordonez could return to the Tigers. Now they'll receive no compensation if he signs elsewhere.

Boston is trying to recover from its own injury-ravaged season. General manager Theo Epstein said this month he wanted to keep Martinez and third baseman Adrian Beltre, another free agent. Boston exercised its $12.5 million option on designated hitter David Ortiz.

The Red Sox did offer Martinez arbitration.

"Wanting to have Victor in the lineup next April is a no-brainer," Boston manager Terry Francona told WEEI radio Tuesday. "When you have to make a decision and you're talking $40, $45, $50 million, four years down the road, that's not quite as easy. I respect that."

Martinez, who turns 32 next month, was signed by the Indians as a 17-year-old shortstop in Venezuela, then developed into an All-Star. He played in Cleveland from 2002 until he was traded to the Red Sox during the 2009 season.

Martinez was limited to 73 games in 2008 because of an elbow injury, but he bounced back to hit 23 homers in 155 games with Cleveland and Boston the following year.