Steve Pearce is retiring, the 2018 World Series MVP said Monday night on Boston radio station WEEI.

"It has been a good run. I have 10 years [of MLB service time] in there. Right now, I am officially retired," Pearce told WEEI.

Pearce, who turned 37 on Monday, was the unlikely hero of the Red Sox's latest World Series championship run. He made his retirement announcement during a rebroadcast of Game 1 of the 2018 Fall Classic. The first baseman hit three home runs in the World Series as the Red Sox beat the Dodgers in five games.

Pearce played 13 Major League seasons for the Pirates, Orioles, Astros, Yankees, Rays, Blue Jays and Red Sox. In 766 games, he was a .254 hitter with 91 home runs. Pearce debuted with Pittsburgh in 2007, and the best season of his career came with Baltimore in 2014, when he hit .293 with 21 homers in 102 games.

When the Red Sox got Pearce in a trade with the Blue Jays in June 2018, he ended up playing a surprisingly key role for their World Series-winning team. Pearce became only the second player to win a World Series MVP Award after being acquired midseason, joining Donn Clendenon of the 1969 Mets.

Pearce became a free agent after the 2019 season and was unsigned. He had previously told WEEI during the offseason that he was "unofficially retired."