BOSTON -- When Dustin Pedroia sat out a Sept. 20 game in Baltimore, the Boston Red Sox explained that he was taking a one-game breather to rest a sore left knee.

Turns out, the injury was more serious than that.

Pedroia underwent surgery to clean up his left meniscus, the team announced Thursday. The procedure -- a partial medial meniscectomy and chondroplasty -- was performed Wednesday by team orthopedist Dr. Peter Asnis at Massachusetts General Hospital. Although the Red Sox didn't outline a rehab plan for Pedroia, they expect the 33-year-old second baseman will "make a full recovery" in time for spring training.

By all accounts, Pedroia was injured when he ranged for a ball up the middle and twisted awkwardly to make a throw on Sept. 11 in Toronto. When he didn't play nine days later, manager John Farrell indicated Pedroia merely needed a day off and wouldn't require an MRI exam or other testing.

Pedroia batted .335 with a .386 on-base percentage after the All-Star break and excelled when Farrell moved him into the leadoff spot in August. In 154 games overall, he hit .318 with 36 doubles, 15 homers and an .825 OPS, his best offensive season since 2011.

But Pedroia also stumbled down the stretch, perhaps because he was compromised by the knee injury. He went 19-for-80 (.238) in his final 18 regular-season games and was 2-for-12 in a three-game AL Division Series sweep by the Cleveland Indians.

This marks the latest in a series of offseason surgeries for Pedroia, who dealt with finger, thumb and wrist injuries after the 2012, 2013 and 2014 seasons.