BOSTON -- For weeks, Rafael Devers has been playing with soreness in both of his shoulders. On Saturday, the Red Sox finally shut him down for the rest of the season.

Devers underwent an MRI on both his left and right shoulder on Saturday afternoon, and the Red Sox subsequently placed the star third baseman on the 10-day injured list with left shoulder inflammation.

The newer of Devers' nagging injuries -- the one to his right shoulder -- worsened in Boston’s 4-2, 12-inning loss to the Twins on Friday night. That, coupled with the left shoulder issue Devers had already been playing through for much of the year, prompted the Red Sox to shut him down as they fell farther out of the playoff race with a week to go in the regular season.

"It doesn't make sense to push him, right?" Red Sox manager Alex Cora said.

Cora said Saturday afternoon that he did not know yet if surgery would be on the table for Devers, as the Red Sox were still awaiting the exact MRI results.

"Whatever it is, we'll take care of it," Cora said.

Devers started Friday's game and went 1-for-4, but entering the top of the 11th inning, Devers was removed from the game. He was laboring with his throws the entire game.

“You saw him throwing today,” said Cora after the game. “It was bothering him. Actually, when he hit inside, he felt it. So he's gonna get an MRI tomorrow, see where we’re at, and probably this is it for him.”

Devers landed hard on his right shoulder on a diving attempt against the Rockies on July 23. He continued to play every day, aside from taking a three-day break from Aug. 27-29.

Instead of looking refreshed at the plate following the late-August respite, Devers looked like a shell of himself as Boston’s postseason hopes faded away.

Devers' right shoulder injury stacked on top of the left shoulder injury he was already dealing with -- that shoulder was the reason why Devers did not play in the All-Star Game after being named an All-Star for the third time in his career.

Down the stretch, the Red Sox saw the signs that Devers' shoulder issues were plaguing him on the field. But Devers fought to stay on the field, a lesson Cora said he first learned from former teammate Xander Bogaerts, and one that was reinforced by current teammate Trevor Story.

"I think Trevor said it best: To set an example, you have to play," Cora said. "That's what you do as a big leaguer. You've got to take pride [in that]. And I think he learned that actually -- the guy that really helped him with that was Xander. Xander always found a way to play."

But Friday proved to be the final tipping point.

"As far as volume, he made some adjustments throughout [to be able to handle playing through the shoulder issues]," Cora said Saturday. "And yesterday, [hitting coach Peter Fatse] was like, 'There wasn't much there today.'"

At the plate, Devers could no longer catch up to fastballs, and in particular was unable to drive them to the opposite field. In the field, Devers lost his arm strength at third base.

"The bat speed, you can see it. And actually, the mechanics of it," Cora said. "He worked on a few things in the offseason, and one of those was to catch up with the fastball. And then we got to a point that he didn't. And teams, they noticed it, and they attacked him. It was relentless. And that started probably a month and a half ago."

In his last 20 games and 84 plate appearances dating back to Aug. 30, Devers has a slash line of .164/.262/.178 with one double, no homers and four RBIs. The 76-78 Red Sox are 7-13 in those games

“Honestly, I’ve never seen this [from Devers],” Cora said prior to Friday’s game.

Early in the season, Devers dealt with pain in his left shoulder and left knee that forced him to miss 11 of the team’s first 24 games, but he caught fire upon his return and stayed hot through the end of July, coming into August with a .979 OPS.

"We're disappointed, because he is basically our offense -- everything [revolves around him]," Cora said Saturday. "He's the guy. And just the last month has been hard to watch."

In 138 games this season, Devers has a line of .272/.354/.516 with 28 homers and 83 RBIs.

His 200th career homer, hit back on Aug. 25, will be his last one until next season.

“It’s tough,” Story said of Devers not returning this season. “I'm super proud of him. I'm proud to call him my teammate. He's the face of the franchise and comes out here and [plays], he's banged up, been banged up for a long time. I think everyone knows that. But he's out here playing, man. He wants to win. He set the tone for everyone to follow. Even if you're banged up, you can still play and kind of set the tone that way. So I'm super proud of him. And happy to be his teammate.”