ATLANTA — Pedro Severino threw his arms wide, signaling himself safe at first with an infield hit that built the Washington Nationals’ lead to five over the Atlanta Braves in the fifth inning Monday night. The play was close, but the game was not. Moments such as that one get lost in 162 games, particularly when they happen in the first four.

But what was remarkable about that moment — other than a member of the otherwise velocity-challenged Washington catching corps beating out an infield hit — was that it constituted an encouraging moment for the depth of a team that has started this season 4-0 and looked downright dominant in the process.

On the day the Nationals suffered their first in-season bruise when Matt Wieters landed on the disabled list, Severino reached base five times and accumulated more hits, two, in one game than Washington catchers had all season. He helped Tanner Roark navigate seven impressive innings in an 8-1 victory over the Braves.

“My concern with him is not really his hitting, it’s catching the way he did today,” said Nationals Manager Dave Martinez, undefeated as a major league manager. “That was outstanding. We want him to call a good game.”

Long before Severino hustled to that extra run, Trea Turner manufactured one. So much of the Nationals’ success this season has centered on scoring first and often, two habits aided by the offensive success of their leadoff men. Adam Eaton reached base all weekend but received a much-needed rest Monday. Turner replaced him and reached twice more, scoring a run.

Then Bryce Harper provided three of them. Some angry Cincinnati Reds fan called Harper overrated Sunday, and Harper responded with a homer. Braves fans remain his most dedicated detractors, and they reveled in their first opportunity to boo him when he stepped to the plate for his first at-bat Monday night. The SunTrust Park organist serenaded him with “The Imperial March” as he walked to the plate for his second.

Harper sent Sean Newcomb’s offering to Tatooine, his third home run in his past two games. Two of them have been to the middle of the field, the direction his home runs go when he is at his best. The Braves walked him four times around that homer, making Monday the kind of evening that became routine in his National League MVP season of 2015.

But Washington has played four games. The Nationals have yet to trail in any of them. As impressive as their start has been, things can change quickly. People get hurt, placing responsibility on those not expected to carry it. Avoiding injuries is not the secret. Preparing for them with depth on the 40-man roster is the antidote.

When a mild oblique strain pushed Wieters to the disabled list Monday, the Nationals called up Severino to replace him, and he finished 2 for 2 with an RBI. Brian Goodwin, who has gotten most of his work as a late-game replacement but hit a grand slam in his one start, hit a two-run single in the ninth inning Monday. Wilmer Difo and Howie Kendrick, the tandem charged with filling in for the still-recovering Daniel Murphy, combined for three doubles as Difo started at second base and Kendrick in left field.

As injuries go, Wieters’s qualifies as relatively insignificant — at least as originally diagnosed. If he is back in a few weeks, the Nationals can mix and match with Miguel Montero and Severino in the interim.

Severino spent the afternoon huddled over a spiral bound notebook, writing notes at his locker. Normally jovial, outgoing and not lacking for confidence, Severino became sheepish when asked what he was writing.

“I just need to remember some things,” he said.

Teammates later revealed that Severino had been stopping by each pitcher’s locker, checking in on how they were feeling and what was working. It had only been a week or so since he had caught most of them. For all of Severino’s natural defensive talent, his game-calling ability has been a teaching point since he made his major league debut in 2015. The 24-year-old is trying to improve it.

“He’s willing to learn, and that’s what’s awesome about him,” Roark said. “He’s keeping notes, and just little things like that is what helps you progress throughout the game.”

Severino caught Roark when the right-hander threw a simulated game in West Palm Beach, Fla., last week. Roark, who had experimented with a simplified delivery all spring, went back to his old windup in that game, hoping it would slow down his mechanics and allow him to stay on line. Working with Severino, he had success against minor league hitters in West Palm Beach.

“Before the game, he said, ‘Let’s do the same thing we did in West Palm,’ ” Severino said. “I said, ‘Let’s do this.’ ”

Roark, like Max Scherzer, Stephen Strasburg and Gio Gonzalez before him, took the mound with a lead. Roark, like all those before him, pitched deep into the game and did not surrender the lead he was given. Nationals starters have averaged more than 6⅓ innings per start and are pitching to a 1.42 ERA.

Stretches of pitching success like that will come and go. The Nationals will lose eventually. The key to sustainability, to getting themselves to October, will be adjusting to adversity and patching holes when they open. The key will be depth players such as Severino staying ready when their name is called and always taking notes for later, just in case.