Jackson Tetreault keeps earning his way into the Washington Nationals’ rotation

After a rough major league debut, Jackson Tetreault has shown he belongs in the Washington Nationals’ starting rotation.

The 26-year-old right-hander allowed just one run in six innings, and the Nationals played error-free defense behind him in Sunday’s 6-4 win over the Texas Rangers.

“This kid comes up here and he’s very much under control. He’s got a good idea what he wants to do, and he works hard every day,” manager Davey Martinez told reporters afterward.

Before he came out for two batters in the seventh, Tetreault had given up two hits and two walks.

A leadoff, first-inning walk followed by a Marcus Semien single were erased erased by a 4-6-3 double play by Corey Seager and an Aldois García line-out, both on first-pitch contact.

Nathaniel Lowe was stranded after a second-inning double when Tetreault struck out Jonah Heim looking and Brad Miller chasing high heat, a 96 mph four-seam fastball up and away.

After walking in the fourth, Seager was erased on a García force-out before Tetreault struck out Kole Calhoun and induced a groundout from Lowe.

After Tetreault tossed a 1-2-3 sixth that included his fourth strikeout, Martinez wanted to see how his rookie starter would handle one more inning.

His starter was still battling and hitting his spots, even though he gave up a single to García and a double to Calhoun.

“The good thing is he went out there,” said Martinez, “He went and threw strikes, a couple guys got on, I thought that was good enough for him. I mean, he was up to 100 pitches by then, but he gave us six strong innings, which was great.”

Martinez replaced him with Erasmo Ramírez, who yielded a sacrifice fly to Heim to score García for the only run against Tetreault.

After a walk to Miller, Ramírez got out of the inning by getting Garver to fly out to Victor Robles in center.

Tetreault’s third start of the season capped a streak of 13 straight innings without allowing an unearned run since giving up seven earned runs in four innings against Atlanta.

In that time, he’s lowered his ERA to 4.25. With enough’s innings to qualify for listing, that ERA would be lower than those of Houston’s Jose Urquidy, the Mets’ Carlos Carrasco or Atlanta’s Ian Anderson, a decent group of mid-rotation starters.

Against the Rangers, Tetreault threw first-pitch strikes or drew first-pitch contact on 13 of the 23 batters he faced, establishing a four-seam fastball that ranged from 92-96 mph and cutter ranging 85-89 mph.

“He fell a little bit behind today on hitters, but he was able to throw that strike when he needed to, which was good,” said Martinez.

‘We’ll go back and look at some things, talk to him tomorrow about some different things that we saw, and then make a couple adjustments and then go from there.”

Heading into the game, the four-seamer and the and cutter were the pitches he’s relied on almost 87 percent of the time and the ones he relies on most often for a swing-and-miss (13 percent for the fastball and 22 percent for the cutter, according to MLB’s Statcast).

Tetreault’s start also completed an entire turn though the rotation and a string of nine straight games where the Nats’ starting pitcher has allowed three runs or fewer.

With 2019 World Series MVP Stephen Strasburg out indefinitely with a stress reaction of the ribs, Martinez said Tetreault is part of the rotation for the foreseeable future.

“He’s going to get an opportunity to pitch every five days,” Martinez said. “And then we’ll see where we go. He’s done well.”