Jacob deGrom was carving through the Atlanta Braves’ potent lineup on Wednesday night, running up his consecutive scoreless innings streak to 18⅓ and displaying some of the best pitching of his career.

He pitched around a two-out single to complete the fourth inning. And then it all gave way to one of the worst possible sights for the Mets: deGrom, their best pitcher, heading into the clubhouse early.

“It’s a bad feeling,” said Asdrubal Cabrera, the Mets second baseman.

DeGrom, who exited the 7-0 loss after only 46 pitches, hyperextended his right elbow while batting, the Mets said later. DeGrom, who hits left-handed, injured his throwing arm when he struck out in the bottom of the third inning, yet still took the mound the following inning.

DeGrom said he had planned to avoid swinging when batting the rest of the game. But after pitching the fourth inning, he told Mets coaches that his right biceps was sore.

“He came through the dugout, said ‘I’m done,’ and went upstairs,” Mets Manager Mickey Callaway said.

DeGrom was not available to speak with reporters after the game because he was headed for a magnetic resonance imaging examination on his arm. The team is expected to receive the results on Thursday morning.

“I’m sure I won’t sleep very good,” Callaway said. “He’s a big part of our team.”

The injury is concerning for several reasons: deGrom’s right elbow has undergone two operations in the past, and he is the best starter in a rotation that has been largely carried by him and Noah Syndergaard.

DeGrom’s injury just heaped more gloom on a dispiriting night for the Mets (17-11). The loss, the fifth in their last seven games, knocked them out of the National League East lead for the first time since the first week of the season, replaced by the much-improved Braves (18-11).

Many of deGrom’s teammates did not notice when deGrom got hurt. He grimaced only slightly when he swung and missed to end his at-bat against Braves starter Sean Newcomb. On the mound, deGrom seemed normal, hitting 94 miles per hour on fastballs to Braves catcher Tyler Flowers, who grounded out to end the fourth inning.

“It’s one of those freaky things in baseball,” said Todd Frazier, the Mets third baseman. “It’s not a contact sport, but there’s injuries everyday.”

In relief of deGrom, Paul Sewald coughed up three runs over three innings. The Braves took the lead in the sixth inning and piled on more runs against Sewald and Robert Gsellman over the next two innings, highlighted by home runs by Ender Inciarte and Johan Camargo.

On offense, the Mets produced only four baserunners against Newcomb, who lasted seven innings, and the Braves bullpen. After the game, Frazier lashed out against the umpires behind the plate for their calls not just on Wednesday, but over the past week. He said they incorrectly called some balls and strikes, faced “no accountability” for their mistakes, and he said he wanted to speak with league officials about it.

“I can’t sit back anymore,” he said. “Something has to be said.”

Frazier continued later: “We lost fair and square. The kid pitched a hell of game but these umpires have got to get better.”

DeGrom’s injury was certainly more important than a disputed strike zone. It was unclear immediately after the game how much time deGrom, who has a team-best 1.87 earned run average, would miss.

Regardless, it was the most significant injury to befall the Mets this season. DeGrom is a more vital player than relief pitcher Anthony Swarzak (oblique injury), and catchers Travis d’Arnaud (season-ending Tommy John surgery) and Kevin Plawecki (expected to return later this month from a hairline fracture in his left hand). DeGrom, a former All-Star, was the only Mets’ starting pitcher to last their entire injury-marred 2017 season, notching his first 200-inning campaign.

DeGrom’s right elbow, however, had been an issue in the past. He underwent Tommy John surgery in 2010, and he had another operation near the end of the 2016 season to move a troublesome ulnar nerve.

Callaway said this injury “wasn’t from his mechanics or an actual pitch so it gives you a glimmer of hope.”

Before deGrom departed, he had been throwing a vintage start, attacking Braves hitters with his array of biting breaking balls and fastballs. Over the years, he has become one of the best in baseball at pitching to the top of the strike zone to neutralize the growing trend of hitters altering their swings to launch fly balls and home runs.

But now, deGrom may need some time to rest and heal. The Mets rotation, the backbone of the team, has received uneven performances from Zack Wheeler, Steven Matz, Matt Harvey and Jason Vargas, who made his season debut last weekend. Seth Lugo, Corey Oswalt, Gsellman and Harvey, who was moved to the bullpen because of his struggles, may be among the rotation options if deGrom misses time.

“Whatever happens, we can sit here and worry about it or cry about it, but that’s not going to do us any good,” Callaway said. “Somebody is going to have to step up if we get some bad news.”

Follow James Wagner on Twitter: @ByJamesWagner.

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Mets Lose Game, First Place and, Much More Significantly, deGrom

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