Marlins Pitching Prospect Karson Milbrandt Cruises Through Triple-A Debut

He was crushing the competition in Double-A to start the season

Nov 9, 2025; Mesa, AZ, USA; Miami Marlins pitcher Karson Milbrandt during the Arizona Fall League Fall Stars Game at Sloan Park. Mandatory Credit: Mark J. Rebilas-Imagn Images | Mark J. Rebilas-Imagn Images

The Miami Marlins have received some devastating news of late involving a couple of the team's top pitching prospects. But another one of the organization's young arms, right-hander Karson Milbrandt, provided a glimmer of hope for Miami fans in his first Triple-A start.

Milbrandt, the Marlins' No. 9 for 2026 on MLB Pipeline, tossed six scoreless innings for the Triple-A Jacksonville Jumbo Shrimp on Saturday. The 22-year-old gave up no runs on two hits and three walks while striking out one in a game Jacksonville eventually lost 2-1 to the Nashville Sounds, the Triple-A affiliate of the Milwaukee Brewers.

The Marlins' 2022 third-round draft pick had been dominating Double-A hitters this year, posting a 1.34 ERA in nine starts with 70 strikeouts in 47 innings. That obviously set the stage for Milbrandt's promotion to Triple-A. And even though he didn't rack up the strikeouts in his first outing with the Jumbo Shrimp, the young righty turned in a strong performance at an important time based on the status of other pitching prospects in Miami's farm system.

Could Karson Milbrandt make his MLB debut this year?

Starter Karson Milbrandt (30) pitches against the Biscuits during the Montgomery vs Pensacola baseball game on opening night in Pensacola on April 3, 2026. | Gregg Pachkowski/Pensacola News Journal / USA TODAY NETWORK via Imagn Images

While Milbrandt just made his Triple-A debut, he could be an option to join the Marlins' rotation later this year. Miami enters Sunday's action with a 30-35 record and is widely expected to be a seller at the trade deadline. If that's the case and the Marlins ship a starting pitcher like right-hander Sandy Alcantara elsewhere, that would open up a spot in the big league rotation.

Looking around at the rest of Miami's farm system, Milbrandt is the only healthy minor league arm currently pitching above High-A. Left-hander Robby Snelling, the Marlins' No. 2 prospect, was called up for his MLB debut earlier this year but then had season-ending elbow surgery. And Miami's No. 1 prospect, left-handed pitcher Thomas White, may also miss the rest of the year after suffering a left shoulder capsular sprain. So, if the Marlins want to add a prospect to their starting pitching staff later this year, Milbrandt would seemingly be one of the top internal candidates.

For now, though, Milbrandt will likely focus on continuing his development at Triple-A. But if he has the same success with Jacksonville that he had at Double-A this year, the young hurler could find himself on a big league mound for the first time at some point this season.