Injuries foil year for 3 top Marlins pitching prospects. A mystery hurts another

Miami Marlins admin September 22, 2026 0 Comments

Injuries foil year for 3 top Marlins pitching prospects. A mystery hurts another

This was supposed to be the season that Marlins fans would get a chance to watch two of the top left-handed pitching prospects in baseball — Thomas White and Robby Snelling.

Injuries torpedoed those plans.

Snelling’s ballyhooed May promotion to the big leagues lasted just one game. Snelling, drafted by the Marlins in the first round out of a Reno, Nevada, high school in 2022, pitched five innings in his Marlins debut on May 8, allowing three runs in five innings against Washington, then reported discomfort in his left elbow after a bullpen session.

The 22-year-old was initially diagnosed with an ulnar collateral ligament (UCL) sprain and placed on the injured list before doctors recommended surgery. Instead of needing a full repair, he instead received an internal brace repair, which could allow him to return next summer if there’s no ongoing lockout.

Because he was on the Marlins’ 40-man roster at the time of the injury, he will get service time for time spent sidelined, accelerating his eligibility for arbitration and free agency.

But there’s also a negative to being on the 40-man roster: When a potential lockout begins Dec. 1, he won’t be allowed to have contact with the team’s medical staff, barring a change in MLB rules, and won’t be permitted to pitch in minor league games next summer if the lockout is ongoing. (He will be allowed to meet with Marlins doctors as late as Nov. 30 to map an offseason program.)

Before his promotion to the Marlins, Snelling pitched brilliantly for Jacksonville, allowing a 1.86 ERA with 44 strikeouts in 29 innings.

“He has true top of the rotation upside,” Marlins president of baseball operations Peter Bendix said.

Since the injury, Snelling has fallen from 39th to 53rd on MLB.com’s top 100 prospect list.

MLB.com ranks Snelling third on its updated list of top 30 Marlins prospects, behind White and shortstop Aiva Arquette.

White began the season 17th on MLB.com’s top 100 prospects list but was moved to 37th after what proved to be a season-ending injury to this throwing shoulder.

After making his final start on May 14, White was diagnosed with a left shoulder capsular sprain, which is a tearing or stretching of the thick tissue wrapping around his throwing shoulder joint. The Marlins recently decided to shut him down for the remainder of the season.

He also missed the start of the season with a Grade 1 right oblique strain sustained during spring training.

White ended up making only seven minor league starts, including five at Triple A Jacksonville, where he had a 5.79 ERA, with 25 strikeouts in 18 ⅔ innings.

In 2025, he was dominant at two lower levels, including 10 starts at Double A Pensacola, where he had a 1.55 ERA and struck out 75 in 45 innings.

Because he’s not on the 40-man roster, White, who turns 22 on Sept. 29, will be able to consult with Marlins doctors and pitch in minor league games during a lockout.

“We are expecting him to be full go,” said Bill Hezel, the Marlins’ director of pitching. “He looks incredible like he always does. We expect him to jump in spring training and be an absolute force. Nobody works harder than Thomas. Physically, he’s an absolute monster.”

An update on the other pitchers ranked among the Marlins’ top 25 prospects on MLB.com:

▪ Right-hander Karson Milbrandt (fifth overall Marlins prospect): For two months, he was one of the best pitchers in minor league baseball, producing a 1.34 ERA in 9 starts at Double A Pensacola, with 70 strikeouts in 47 innings.

Everything changed after his promotion to Triple A Jacksonville, where he finished 0-8 with an 8.39 ERA in 16 games and 15 starts. One major problem: He walked 62 in 64 1/3 innings, on top of allowing 62 hits, after walking just 17 in 47 innings in Pensacola.

Hezel recently indicated that the team isn’t too concerned, noting he generated “a lot of swing and miss” during a couple of late-season starts.

“All players react differently” to promotions to Triple A, Hezel said. “It’s fundamentally different. There’s an adjustment period all guys go through, and it’s hard to do that while facing the hardest competition you’ve faced in your life.”

▪ Pitcher Kevin Defrank (ninth overall): He’s the top rated Marlin among prospects who haven’t played above rookie ball.

At 19, the Dominican Republic native already reaches 100 mph on the radar gun. But he didn’t pitch this season, mostly because of a right bicep tendon injury ended his season in May.

“He did some really promising things in spring training,” Hezel said. “He’s a special talent, pretty mature, works like a pro.”

He had a 3.19 ERA in 10 starts in the Dominican Summer League last year.

MLB. com says the 6-5 Defrank is “quite physically mature for his age with an ankle, muscly frame. Teenage pitching prospects are incredibly risky, but he’s checking every box you’d want to see, including impressive makeup and leadership. Early returns point to him becoming Miami’s best international pitching prospect since Eury Perez.”

.▪ Left-hander Ethan Kleinschmit (12th): Drafted in the second round out in July, Kleinschmit hasn’t pitched since making 15 starts for Oregon State this season (9-2, 3.74 ERA, 97 strikeouts in 77 innings).

But there’s no reason for alarm; none of the pitchers drafted by the Marlins in July were used in a minor-league game. They instead worked out at the team’s Jupiter Academy, which allowed them time to focus on development.

MLB.com says he “shows the ability to fill up the strike zone with four pitches. While he won’t overwhelm anyone with pure stuff, he makes up for it with movement and feel for pitching.”

▪ Right-hander Ryan Peterson (15th): Drafted in the second round of this year’s draft, Peterson made 15 starts for Sam Houston State this season. Peterson, who had a 3.38 ERA and 105 strikeouts in 88 innings, had “one of college baseball’s best curveballs,” per MLB.com’s scouting report.

“If he threw harder, he might have been a first-rounder. He not only throws strikes with all three of his primary offerings, but he also locates that well, enhancing his mid-rotation profile.”

▪ Left-hander Nate Payne (16th): Drafted in the 18th round in 2024 out of a Harrisonburg, Penn., high school, Payne had a 3.68 ERA in 19 starts at High A Beloit, after making four starts at Jupiter. He closed the season 147 strikeouts, but also 47 walks, in 111 innings.

MLB. com says Payne Payne has No. 4 starter upside thanks to his “workhorse size, repeatable delivery and breaking balls — or perhaps more if his added velocity sticks.”

▪ Right-hander Jacob Kisting (21st): Acquired in the Liam Hicks trade with Tampa, Kisting was exceptional before and after the trade, producing a 10-0 record with a 1.72 ERA in 23 appearances (21 starts) at High A in the Rays’ system and Double A in the Marlins’ system.

He allowed just 100 base-runners in 110 innings, with 127 strikeouts.

“He’s a big, physical, a guy who throws strikes,” said Hector Crespo, the Marlins director of minor league field operations. “Has a feel for multiple pitches and has an ability to command and keep hitters off balance. He doesn’t have a 98 to 100 mph fastball, but he’s at 92 to 95 with real movement to the fastball, and a splitter/changeup.”

Here’s my early September piece on how the Marlins’ top hitting prospects have done this season.

Here’s my piece on what happened to former Marlins first-rounder Noble Meyer.