After a long, 10-game road trip, the Mets returned to Citi Field before their bats arrived.

The Mets opened a seven-game homestand quietly, getting shut out by the Nationals for a third straight loss, 5-0, in front of 20,507 on Tuesday night.

Jose Butto was wild, the top of the sixth inning was wacky and the Mets (14-10) failed to capitalize against the last-place Nationals (8-14).

The Mets finished with just five hits — only one after the fifth inning — and were silenced by New Rochelle native Josiah Gray, who struck out nine in six scoreless innings.

“We had [13] strikeouts and one walk,” manager Buck Showalter said after the Mets’ fourth shutout this season. “That’s usually not our game.”

The Mets were down two by the third inning and never clawed their way back.

Their best threat came in the fifth, when a double from Brett Baty, an infield single from Francisco Alvarez and a walk from Brandon Nimmo loaded the bases with two outs.

But Starling Marte, who has started slowly, worked a full count against Gray before swinging over the top of a diving cutter, allowing Gray to escape.

Gray, who entered with a 12.00 ERA in three lifetime starts against the Mets, twirled a gem.

“He just made good pitches today, to be honest with you,” Luis Guillorme said after going 0-for-3 with two strikeouts and one significant defensive misplay. “There’s not much to it.”

Marte’s at-bat was the last time the Mets had a runner in scoring position.

Gray and righty Mason Thompson faced the minimum from the sixth inning on, the only hit a ninth-inning single from Francisco Lindor — who was quickly erased by a Pete Alonso double play.

Butto, who had not pitched in nine days and only had been recalled earlier Tuesday, pitched as if he were feeling more rusty than rested.

Of the 93 pitches the righty threw, only 46 were strikes en route to walking six in 4 ²/₃ innings.

“I battled as best as I could, and things just didn’t come out the way that I wanted them to,” Butto, who only was informed Monday he would start Tuesday, said through translator Alan Suriel.

Despite the lack of control, he pitched well enough to keep the Mets afloat. Butto allowed just two runs on four hits, doing his best work with runners on.

He limited the Nationals’ lineup to 1-for-5 with runners in scoring position and filled in adequately for Max Scherzer, whose suspension prompted Butto to make the start.

Butto dug the hole in the second, when Keibert Ruiz crushed a home run to center field, and made it larger in the third, when the 25-year-old walked a pair before Joey Meneses drilled an RBI single to center.

The Mets still had a pulse until the sixth inning, which could have been over after three batters.

The third, Alex Call, grounded what looked like a double-play ball that would have been the second and third outs.

But Guillorme never saw it.

He broke to his right, and the ball shot through to his left, Guillorme lifting his hands in confusion. A would-be double play became a single to right field.

“I had no idea where it was,” Guillorme said. “I hate plays like that. I hate not picking up my pitchers. It cost him a couple extra pitches and a couple runs.”

Jimmy Yacabonis, a New Jersey native making his home debut, had to then face five more batters and the Nationals gained separation.

The next batter, Luis Garcia, might have struck out on a check-swing call that Showalter wanted but did not get.

Given another chance, Garcia knocked a two-run double to right-center. Meneses followed with an RBI single, and a 2-0 game had become a 5-0 game.

“We weren’t real crisp defensively tonight,” Showalter said on a day Lindor made his first error of the season trying to tag Lane Thomas, advancing from first to second in the fourth inning, but dropping the ball in the process.

The defensive issues would prove inconsequential because the Mets’ offense never threatened.

The Mets, who beat up the Nationals in winning 14 of 19 last season, have begun this year 0-for-1 against Washington.