NEW YORK -- Right-hander Jordan Weems entered Nationals camp this spring with one approach, and he left for Triple-A Rochester with another. Two months later, that shift in outlook helped lead to a Major League callup on Tuesday.

“I came into Spring Training with kind of the older mindset of just trying to throw the ball past everybody and kind of just not being under control when it comes to a mechanical standpoint,” Weems reflected at his locker pregame in the visitors’ clubhouse at Citi Field. “I think these past two months have been a big stride for me just to understand that the mechanics are a huge thing; you can’t rely on just your arm strength.”

After getting the call at 11:30 p.m. on Monday and arriving in New York 12 hours later, Weems pitched a scoreless seventh inning in the Nats’ 10-0 loss to the Mets. In a game in which zeros were hard to come by, Weems retired the side facing the Mets’ Nos. 2, 3 and 4 hitters: Starling Marte (flyout to right field), Francisco Lindor (strikeout looking) and Pete Alonso (strikeout swinging). Of his 15 pitches, Weems delivered 10 with a fastball that topped out at 98.7 mph.

“He threw the ball well, he really did,” manager Dave Martinez said. “He said his heartbeat was going a little bit fast and I kind of figured that, but it was a good night to get him in there and get him to relax a little bit. But the ball came out really well, and he threw a couple nice sliders as well. I’m looking forward to watching more of him.”

Weems, 29, had made 16 big league appearances across two seasons with the Athletics and D-backs before he signed a Minor League deal with Washington on March 8. He was in one of the last rounds of roster moves during Spring Training, and the Nats kept a close eye on him as he progressed in the organization.

In 19 games with the Red Wings, Weems was 2-1 with a 3.38 ERA and six saves in seven opportunities. He averaged 12 strikeouts per nine innings, and he issued only five walks across 24 frames.

“We feel like he has his feet under him,” Martinez said. “He checks off all the boxes that we want to see, and he’s going to get an opportunity to help us.”

Although Weems was selected by the Red Sox in the third round of the 2011 Draft, he is still somewhat new to pitching. Weems was drafted as a catcher, and he did not shift to pitching until 2016. Of his Minor League experience, 242 games have been played behind the plate and 192 on the mound. Six years into his new role, Weems still is soaking up what he needs to learn.

“I love catching -- I still miss it, still miss hitting -- but I feel like I made the right choice, obviously,” Weems said. “I probably wouldn’t have got the opportunity if I was still catching. You’ve got to have that ability to see the writing on the wall when somebody tells you, ‘Hey, you’re not good enough to do it.’ It’s a tough pill to swallow. Fortunately enough, I was blessed with a good arm, and I just try to take in as much as I can from all the guys who have been doing this for a long time.”

While in Triple-A, Weems sought out knowledge from pitching coach Rafael Chaves, veteran Tyler Clippard and current Nats reliever Carl Edwards Jr., among others. Martinez noticed Weems’ work translate into an effective attack of the strike zone and a strong pitch mix that includes a fastball, slider and splitter.

As for his mechanics, one of Weems’ key takeaways from the first two months of the season has been to throw “the quality strike, not just the strike.”

“I think it’s just having confidence and just knowing that you don’t have to make your stuff better,” Weems said. “Just believing in it and knowing that your stuff’s good enough to be here.”

He showed that on the mound Tuesday night.