BOSTON — Red Sox left-hander Chris Sale is receiving treatment for inflammation in his elbow that will shut him down for the rest of the regular season, another blow to the defending World Series champions whose postseason hopes appear all but dashed.

Orthopedist Dr. James Andrews gave Sale an injection of platelet-rich plasma on Monday and said he will be re-evaluated in six weeks.

Looking beyond this frustrating season, the treatment could be good news for the club, which feared Sale might need Tommy John surgery. That would likely have cost him the 2020 season.

Boston was off Monday and was 6½ games out of a wild card spot.

The 30-year-old Sale was coming off two solid starts in which he combined for 25 strikeouts — including the 2,000th of his career — and allowed only three runs in 14 2/3 innings.

Sale, a seven-time All-Star in his 10th season, was the fastest to reach 2,000 Ks in major league history.

Last season, Sale dealt with shoulder soreness after the All-Star break, limiting him to 29 innings.

He was also limited in the postseason, but closed out the World Series by striking out then-Los Angeles Dodgers infielder Manny Machado to clinch Boston’s fourth title in 15 seasons.

Sale signed a six-year, $160 million contract in March that includes $50 million in deferred money.

Sale never shied away from responsibility for his struggles this year. His velocity was down in April, and he took the loss in five of his first six starts.

“I’m struggling and I don’t know if I’ve really pitched like this in my life,” Sale said after a loss to Toronto on April 9. “It’s a tough spot to be in. But I’ve got guys up here fighting and I’ve got to keep fighting. There’s no giving up. If something’s not working, you got to go to something else.”