Pearce, who was named the MVP after hitting three home runs with eight RBIs as Boston defeated the Los Angeles Dodgers in five games, made the announcement Monday night on WEEI. The Boston radio station was rebroadcasting Game 1 of that World Series, with Pearce providing some commentary.
"You know what? It has been a good run. I have 10 years in there. Right now I am officially retired," he said.
Pearce was asked during the rebroadcast about the allegations that the Red Sox illegally used the replay room to steal signs in 2018. Major League Baseball is investigating the allegations but has not yet released its findings.
"That's such a joke to us," Pearce said on WEEI. "When it came out, we were all kind of joking about it. We just want this to pass us. We won it fair and square. Whatever they accused us of, we were all kind of like, 'I can't believe this is even an issue.' Once the report comes out, we're all going to be free.
"You don't like it, especially that we were the champions and individually I have that award. And we have this floating over our head when we just had such an unbelievable season. We had the perfect team and great camaraderie with everybody, and then this gets thrown out here. We're just like, 'What the heck?'"
Red Sox interim manager Ron Roenicke told reporters on Tuesday he'd like to see MLB release its findings before the sport returns from its hiatus due to the coronavirus pandemic.
"It would be nice to get that done before we come back again. Before we start training again, it would be nice to have that behind us," he said. "I haven't heard when they would do something. Somebody said something about a comment they would like to have it out before we started training camp again, and that would be nice if we could do that."
Roenicke said he plans to reach out to Pearce via text. Roenicke, who was the bench coach on the 2018 club, applauded the job Pearce did after coming to Boston in a midseason trade.
"What Steve did for us in '18 was pretty incredible," he said. "He walked into a situation where we were playing really well, and sometimes that's hard to come to a team where you don't know that many guys and fit in. From the get-go, from the first game that he played, he fit in great. His personality worked really well, and then what he did on the field was outstanding."
Pearce, who turned 37 on Monday, played for seven teams in his career and hit .254 with 91 home runs and 303 RBIs in 766 games.
ESPN's Joon Lee contributed to this report.