NEW YORK — Winners of five straight, the New York Mets have a big test brewing:

Jacob deGrom is getting an MRI.

The two-time Cy Young Award winner was pulled after five innings with right side tightness in his return from an injury to a similar area, but the bullpen closed out a four-hitter as New York beat the Arizona Diamondbacks 4-2 Sunday.

DeGrom (3-2) was perfect through four innings but laboured in the fifth, then called for trainer Brian Chicklo after throwing two warm-up pitches ahead of the sixth. DeGrom exited and went straight to the clubhouse.

“No pain whatsoever, just tightness,” manager Luis Rojas said. “That's what he told our trainer.”

The right-hander was coming off a 10-day layoff, skipping his previous turn in the rotation because of a right lat issue. Rojas said the side tightness — centred around the lower-right side of his back — seems to be a different issue.

Prior to Sunday, deGrom had a 0.51 ERA and 59 strikeouts in 35 overpowering innings.

New York expected to have results of the MRI by Sunday night.

“I want to sit and wait and see what it is, and then we can plan as a group what's next,” Rojas said.

The 32-year-old deGrom threw 68 pitches over five innings, allowing a run with six strikeouts, a hit and three walks.

DeGrom walked three during a 29-pitch fifth inning, just the second time in his career he’s done that. His previous three-walk inning was May 13, 2018, at Philadelphia. He was pulled after one inning in that game, his first back from the injured list.

Right-hander Miguel Castro relieved deGrom with New York ahead 2-1. He hit a batter and walked another before completing a scoreless inning.

Jacob Barnes worked a perfect seventh before allowing Asdrúbal Cabrera’s solo homer in the eighth, and Edwin Díaz got five outs for his fifth save.

It was Díaz’s second career five-out save and first with the Mets of more than three. He stranded Nick Ahmed in the ninth after catcher James McCann, third baseman Jonathan Villar and Díaz let Ahmed’s popup fall between them for a single.

Michael Conforto had two hits, an RBI and a superb catch against the right-field wall, and New York improved to 16-13 — again achieving its season best at three games over .500.

The Mets matched their longest winning streak since August 2019. They also beat the Diamondbacks for the 10th straight time at Citi Field.

Arizona has lost six in a row overall and totalled just eight runs during this three-game sweep in Queens. Rookie right-hander Riley Smith (1-2) allowed two runs, four hits and a walk in four innings, striking out one.

“We are at a very critical point right now where we have to find a way, and we will,” said frustrated manager Torey Lovullo, who was ejected in the seventh inning. “We put ourselves in a very good position when we do the little things the right way. Those will be my messages to the players over the coming days.”

DeGrom played catch several times last week after being scratched Tuesday and felt confident he was ready to return.

He reached 100 mph twice in the first inning but didn't look entirely comfortable, shaking out his arm behind the mound at one point. Still, he opened with four perfect innings for the first time since retiring 15 straight to start against San Diego on June 1, 2015, per MLB.com.

His rocky fifth began with a free pass to David Peralta, and Stephen Vogt followed with a long double.

Center fielder Kevin Pillar and Conforto both dived for Vogt's drive on the warning track but came up short. Pillar's face clipped Conforto's left cleat on the play, and Pillar appeared to be bleeding on the side of his head while he was checked by a trainer. He remained in the game.

DeGrom walked Eduardo Escobar to load the bases with no outs and fell behind Ahmed before inducing a 4-3 double play that cut New York's lead to 2-1. He walked Daulton Varsho, then struck out pinch-hitter Christian Walker.

The Mets do-it-all ace also helped build the lead. DeGrom placed a perfect bunt single down the third-base line during a two-run third inning, his seventh hit in six games. The former college shortstop is batting .467 this season.

DeGrom scored on Conforto's two-out single, and Francisco Lindor also lofted an RBI sacrifice fly in the inning.

Rojas wasn't sure when deGrom developed the side tightness, especially since he was so active throughout the game between the 29-pitch inning and running the bases. DeGrom didn't mention the discomfort until the sixth inning.

“He was down,” Rojas said. “He wanted to pitch through it. He was asking us, but he did the right thing.”

The Mets got their third run on pinch-hitter Patrick Mazeika's bases-loaded walk against J.B. Bukauskas as light rain began in the sixth. Dominic Smith added an RBI single in the seventh.

SWEET 16

Barnes survived a 16-pitch at-bat against Pavin Smith in the eighth inning, the longest plate appearance in the majors this season. Smith fouled 11 pitches before striking out looking at a fastball.

TOSSED

Escobar was ejected by plate umpire Manny Gonzalez after striking out swinging in the seventh. Lovullo came out to argue and was also booted by Gonzalez.

TRAINER'S ROOM

Diamondbacks: OF Ketel Marte (right hamstring) is expected to workout at Chase Field on Monday or Tuesday to determine next steps in his recovery. He's been running and taking batting practice and could begin a rehab assignment soon.

Mets: RHP Drew Smith was recalled from Triple-A Syracuse, and RHP Trevor Hildenberger was optioned.

UP NEXT

Diamondbacks: Arizona opens a home series Monday against Miami with RHP Luke Weaver (1-3, 6.07) on the hill. The Marlins hadn't announced a starter.

Mets: Get Monday off before hosting Baltimore to open a two-game series. New York RHP Marcus Stroman (3-3, 2.12) faces Orioles LHP John Means (4-0, 1.37), who will be pitching on five days' rest following his no-hitter against Seattle last week.

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