Boston pitcher Jon Lester acknowledges the crowd at Fenway Park as he leaves during the eighth inning of Game 1 of the 2013 World Series against the St. Louis Cardinals. Lester finishes his career with a 200-117 record and a 3.66 ERA in 452 career games. AP Photo/David J. Phillip

Three-time World Series champion Jon Lester announced Wednesday that he’s retiring from baseball.

Lester, who won two titles with the Boston Red Sox in 2007 and 2013, and another with the Chicago Cubs in 2016, will go out as one of the greatest postseason pitchers of all-time.

His 154 postseason innings rank eighth-most in baseball history, while his 2.51 ERA ranks fifth among all pitchers with at least 100 postseason innings.

The 38-year-old was 7-6 with a 4.71 ERA in 141-1/3 innings between the Nationals and Cardinals last year before he decided it was time to hang up the cleats.

“It’s kind of run its course,” Lester told ESPN while announcing his retirement. “It’s getting harder for me physically. The little things that come up throughout the year turned into bigger things that hinder your performance. I’d like to think I’m a halfway decent self-evaluator. I don’t want someone else telling me I can’t do this anymore. I want to be able to hand my jersey over and say, ‘thank you, it’s been fun.’ That’s probably the biggest deciding factor.”

Lester, who started 26 games for the 2005 Portland Sea Dogs and one in 2007, began his impressive career in Boston in 2006, though it was quickly paused due to a battle with cancer. He was diagnosed with anaplastic large cell lymphoma and missed time due to chemotherapy treatments, but made a heroic return in ’07, when he pitched in three playoff games, including a five-inning scoreless performance in Game 4 of the World Series.

The 6-foot-4 lefty quickly became a fixture in the Red Sox rotation, where he spent the better part of seven seasons as the team’s ace.

Lester peaked in 2013, when he posted one of the most dazzling playoff runs in history. He averaged seven innings a start while putting up a 1.56 ERA and going 4-1 in five starts to lead the ’13 Sox to another title.

Overall, he went 110-63 with a 3.64 ERA in Boston before he was traded in the 2014 dump-off as the Sox unloaded much of their roster in the midst of a disappointing year.

When he hit free agency, it was expected that former Red Sox boss Theo Epstein would go hard to bring Lester to the Cubs. The Sox had fumbled their attempts to extend him in previous years and Lester seemed content to walk away as he joined Chicago on a six-year deal worth $155 million.

The Red Sox took a while to recover after that, eventually spending $217 million on David Price and later trading for Chris Sale in their attempt to replace Lester atop their rotation.

Lester continued his postseason dominance while with the Cubs and had a 2.02 ERA in six playoff appearances to help them break their 108-year World Series drought in 2016.

Of the six years he was under contract with the Cubs, two were great, two were good and two were sub-par as he finished his career in Chicago with a 3.64 ERA, the same as his ERA in Boston. After the contract expired in 2020, he signed a $5-million deal with the Washington Nationals for 2021 and was traded to the St. Louis Cardinals midseason.

He finishes his career with 200 wins, 2,488 strikeouts and a 3.66 ERA, numbers that probably aren’t Hall of Fame worthy on their own, but paired with his historic postseason numbers could give voters something to think about. His numbers are similar to those of Curt Schilling, who had 217 wins and a career 3.46 ERA but also pitched his best in the playoffs.