A spate of serious injuries has the Braves in leak-plugging mode, and not just with regards to Ronald Acuña Jr. The team also found itself with an unexpected rotation hole after AJ Smith-Shawver was diagnosed with a Grade 2 oblique strain last week, with which Smith-Shawver, their No. 1 prospect, will miss 6-8 weeks.

So, Atlanta plans to fill that hole with another top prospect.

The Braves are set to call up right-hander Spencer Schwellenbach, the team's No. 3 prospect, to make his MLB debut in Smith-Shawver’s spot in the rotation on Wednesday against the Nationals. The 23-year-old Schwellenbach is being called up straight from Double-A Mississippi after making just two starts at that level.

“He’s a college guy who’s gotten results,” manager Brian Snitker said. “It’s attractive when you get guys out. That’s the way you get noticed.”

Schwellenbach, who was in the Braves’ clubhouse prior to their 2-0 win on Tuesday, said he had been at Triple-A Gwinnett to throw a bullpen, with the expectation that his next start would come there. He was then informed that his next start was actually coming in Atlanta, less than 13 months after making his pro debut last April.

“I was not expecting it,” Schwellenbach said. “I was totally taken off guard and very happy about it.”

But the Braves had been hatching this plan for a while -- really ever since learning the severity of Smith-Shawver’s injury last week. They adjusted their bullpen plans the past few days and leaned on Charlie Morton to eat more innings than they typically would have during Monday’s loss in preparation for Schwellenbach’s debut. The righty has averaged 5.63 innings per start this year but he is still relatively new to starting. He only pitched as a closer in college.

“You look at his numbers, they’re really, really good,” Snitker said.

That’s certainly true. Schwellenbach is 4-1 with a 1.80 ERA and 51 strikeouts in 45 innings across eight starts this season -- six at High-A Rome and two at Double-A Mississippi. He pitched 13 scoreless innings with 17 strikeouts against just one walk in his two outings after being promoted to Double-A.

Schwellenbach was the Braves' second-round pick in the 2021 MLB Draft out of the University of Nebraska, where he won the 2021 John Olerud Award as the best two-way player in college baseball. The Braves drafted him as a pitcher knowing he would need Tommy John surgery before his debut; as it was, Schwellenbach spent parts of 2021 and all of 2022 recovering from the procedure.

The Braves got a good look at him during this year’s Spring Breakout, and he’s gotten little but excellent results since his pro debut in 2023. In two Minor League seasons, Schwellenbach is 9-3 with a 2.21 ERA and 106 strikeouts in 110 innings over 24 starts.

“I think when I wake up tomorrow it’s really going to set in,” Schwellenbach said. “I’ve only pitched [about] 100 innings in the Minors. I was just trying to get my reps in, get my pitches in, work on recovering good. Now I’m here and I can’t be happier about it.”

Atlanta still needs to make a corresponding move before officially activating Schwellenbach, likely to come after Tuesday’s game against Washington.