Three months ago, 20-year-old right-hander AJ Smith-Shawver was on the roster for the Class-A Rome Braves.

On Friday night, the Atlanta Braves rookie will continue his meteoric rise through the organization when he makes his first major league start, facing the visiting Washington Nationals in the opener of a three-game series.

The Braves have won five straight games after a dramatic 13-10, 10-inning win over the New York Mets on Thursday. The Nationals, who have lost four straight, had their scheduled Thursday home game against the Arizona Diamondbacks postponed because of hazardous air quality caused by Canadian wildfires.

Smith-Shawver (0-0, 0.00 ERA) will be opposed by right-hander Josiah Gray (4-5, 3.09) in the second series between the two clubs this season. The Braves won two of three games at Washington in the opening series of the season.

Smith-Shawver needed just 28 minor league starts to reach the majors. This year, he made three starts for Rome, two for Double-A Mississippi and two for Triple-A Gwinnett, going a combined 2-1 with a 1.09 ERA and 45 strikeouts in 33 innings.

Smith-Shawver made his major league debut on Sunday at Arizona. He pitched 2 1/3 scoreless innings out of the bullpen and allowed no hits and one walk while striking out three.

"It's kind of surreal," Smith-Shawver said after being called up. "The Braves had a lot of people that helped me develop and really guided me. I didn't really know exactly what I was doing when I first got into it, and I think the guys around here, around this organization, really gave me the right tools to compete and gave me the opportunity."

Smith-Shawver was a seventh-round draft choice in 2021 out of Colleyville (Texas) Heritage High School who did not start pitching regularly until the summer of 2020.

Gray will make his 13th start. In his latest appearance, on June 2 against the Philadelphia Phillies, he gave up four runs on six hits -- two of them home runs -- with two walks and four strikeouts in 5 1/3 innings.

Gray has made five career starts against Atlanta, going 1-2 with a 3.33 ERA. He took a loss against the Braves on April 1 when he surrendered a season-high five runs in five innings during a 7-1 defeat. The right-hander served up three home runs in that contest.

Atlanta is coming off a dramatic three-game sweep of the rival Mets. The Braves came from behind to win each game. They trailed by three runs in the first two games and by four runs in the finale. It was the first time since the team moved to Atlanta in 1966 that it won three straight games when trailing by at least three runs.

Washington's Joey Meneses has reached base in a career-best 15 straight games and is hitting .362 (21-for-58) during the streak. He has reached safely in 25 of his past 26 games.

The Nationals made a roster move on Thursday, claiming left-hander Joe La Sorsa off waivers from the Tampa Bay Rays and assigning him to Triple-A Rochester. He will be joined there by center fielder Victor Robles, who will begin a rehab assignment after spending time on the injured list with back spasms.

"It's really been tough for (Robles)," Washington manager Dave Martinez said. "He's been frustrated because he was hitting the ball really well and playing well."