Mets' Steven Matz pitches in the second inning against the...

Mets' Steven Matz pitches in the second inning against the Nationals on July 3, 2017. Credit: Mitchell Layton / Getty Images

WASHINGTON — Steven Matz missed the first two months of the season with an elbow injury suffered during the closing days in spring training.

But for the Mets, the Long Island lefthander has been worth the wait.

Lost in the Mets’ 3-2 walkoff loss against the Nationals was Matz’s latest outstanding effort. Though he did not factor in the decision, Matz tossed seven shutout innings, matching the Nationals’ Stephen Strasburg in what became a classic pitchers’ duel.

“I’ve been really impressed,” Mets manager Terry Collins said. “This guy, he has not complained. He’s done his work, worked hard, and pitched great. He makes his pitches count. He uses them — doesn’t just use his stuff to set up pitches.”

In Matz’s five starts since coming off the disabled list, he has pitched seven innings four times, including his last two outings which have been scoreless. With Monday’s performance, Matz lowered his ERA to 2.12.

“You just want to go deep into the game as a starting pitcher,” said Matz, who has not allowed a run in 17 consecutive innings.

After dealing with trouble through his first four innings, Matz did not allow a baserunner the rest of the way, retiring the last 10 batters that he faced.

“I was really happy I was able to go seven innings after kind of having a heavy workload the first few innings,” said Matz, who scattered four hits while walking two and striking out four.

Despite beginning the season on the shelf, Matz has helped to steady the Mets’ starting rotation. He has logged 15 scoreless innings in his career at Nationals Park and has pitched at least six innings in 10 straight outings dating back to last season.

“You knew it,” Collins said. “We’ve seen it in the past. He’s got a chance to be real good.”

Meanwhile, Strasburg encountered real trouble just once. It came in the fourth inning, when his command suddenly escaped him. He walked the bases loaded, then engaged in a long battle with Travis d’Arnaud.

But after a flurry of curveballs, Strasburg froze d’Arnaud with a 97 mph fastball to end the inning. With that, Strasburg settled into a groove. He did not allow another baserunner the rest of the way.

“You talk about two guys that battled,” Collins said. “You don’t get very many chances against Stephen Strasburg . . . When you get good pitchers on the ropes, you better do some damage because you’re not going to get them very often.”

n Extra bases

For now, injured outfielder Michael Conforto remains the Mets’ only All-Star Game representative. “I was a little surprised,” said Collins, who insisted that righty Jacob deGrom and outfielder Jay Bruce warranted consideration. Both could still make the National League team as replacements . . . Jose Reyes collected two hits. He’s hitting .304 over his last 17 games . . . Collins backed third base coach Glenn Sherlock, even though his decision to send Brandon Nimmo in the eighth inning resulted in an out at the plate. Said Collins: “You’ve got to make a guy make a good throw.” The game was still scoreless in the eighth when Brian Goodwin threw out Nimmo trying to score on Reyes’ hit.

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