MLB: Boston Red Sox at Cleveland Indians
David Richard / USA TODAY Sports

Boston Red Sox left-hander Chris Sale underwent Tommy John surgery on Monday, according to the team. The operation comes more than a week and a half after the Red Sox announced that Sale would require the procedure. He will miss whatever can be salvaged of the 2020 season, as well as the beginning of the 2021 season.

Sale, who also turned 31 years old on Monday, had been plagued by arm trouble all spring. The operation ensures that he'll be impacted by health woes for three consecutive years, as last season he made his fewest starts (25) since becoming a full-time starter in 2012. The 2019 season was uncharacteristic for Sale in other regards, too. He posted the worst ERA+ of his career (109), as well as the lowest quality start rate (52 percent).

Prior to last season, Sale had agreed to a five-year extension worth $145 million that kept him from hitting the open market over the winter. The contract did not kick in until this season, making this an ominous start to the new pact.

It's unclear how the Red Sox will replace Sale, in part because it's unclear if the 2020 season will be played at all in response to the spread of the novel coronavirus. Even if the season does get started sometime over the summer, it's not as though Boston was prioritizing winning: over the offseason, they traded Mookie Betts and David Price to the Los Angeles Dodgers. The Red Sox did not make many notable additions, either, leaving them with a flimsy rotation.

Sale joins New York Mets right-hander Noah Syndergaard as well-known pitchers to undergo Tommy John surgery over the past week. Typically, pitchers tend to complete the grueling rehab process and return to game action in about a year's time, though that can vary.