JUPITER, Fla. – Kevin Defrank isn’t just the next big thing in Marlins camp. He might be the next big thing in the wide landscape of Minor League pitching prospects.
Standing 6-foot-5 already at only 17 years old, the right-hander has headed stateside for his first Spring Training at the Marlins complex in Jupiter and comes to Florida with tons of momentum in his young career. After signing for $560,000 in January 2025, he posted a 3.19 ERA with 34 strikeouts in 31 innings in the Rookie-level Dominican Summer League last year.
Those are solid foundational numbers for a first taste of pro ball, but what excited scouts and Marlins officials most was the quality of present stuff and the projection of what could still be coming. Miami’s No. 6 prospect sat around 97 mph with his fastball in the DSL and has pushed it into triple-digits with regularity this spring. His changeup shows great fade at 88-91 mph and is beyond the changeups of many his age, profiling like a potential plus pitch, and an upper-80s slider shows enough sweep to be another at least above-average offering.
“Beyond what you can read in the stat line, the makeup is pretty unreal,” said Marlins director of player development Rachel Balkovec. “I would say what excites me the most is how much he grew last year and how much I think we're going to see him grow again this year because of his discipline, his work ethic, and just the physicality that he gained. I think he’s exploded onto the map.”
COMPLETE MARLINS PROSPECT COVERAGE
Miami has been down this road with truly promising and extremely young pitching prospects before. Thomas White, who also stands 6-foot-5, has become the game’s No. 17 overall prospect after only two full seasons in pro ball, and before him, the 6-foot-8 Eury Pérez was the big phenom who debuted in the Majors at 20 years old in 2023. Pérez, who still only turns 23 next month, is still mostly talked about for his potential after Tommy John surgery knocked him out for the entire 2024 season and has held him from reaching 100 innings over a single season in The Show yet.
The Marlins would obviously like to preserve Defrank’s arm and elbow health so early in his career, but understand there are many factors at play beyond him throwing so hard at a young age.
“For how much research has been done and how much time has been spent, we still don't know exactly what causes an injury,” Balkovec said. “We're also working with young professional athletes who don't like to sleep and like to eat gummy worms for breakfast. So we just try to control what we can control.
“Our philosophy is heavily focused on strength and conditioning and nutrition and getting those guys prepared from a physical baseline to withstand not just our aggressive pitching training, but also our aggressive defensive training, our aggressive hitting training. All that to say, how do we get them prepared? I would say it's [in] the weight room and in the cafeteria.”
Keeping Defrank healthy for 2026 and beyond is tantamount because with his current level of stuff, he just needs the innings on the field to prove why he should be considered a Top 100 prospect across the sport and a key piece of future Miami Major League rotations.
“People forget that he arrived to us throwing 93,” Balkovec said. “It's a testament to his work and to our staff's work in the weight room, and at the Academy, [people] messaging correctly. And now he's throwing 102.”
Bounceback candidate: Andrew Salas (No. 12)
In 2023, Padres catcher Ethan Salas signed with the Padres for $5.6 million in January and jumped to Single-A Lake Elsinore for his first Minor League debut only days before his 17th birthday. Two years later, his brother Andrew joined the Marlins organization for $3.7 million and similarly skipped over the complexes to debut with Single-A Jupiter. With 453 plate appearances, he was the only age-17 Minor Leaguer to reach the qualifying standard in 2025, and well, he performed like it with a .186/.319/.245 line, three homers and a 74 wRC+ in 104 games with the Hammerheads.
On the positive side, Salas ran a 15.9 percent walk rate that ranked fifth in the Florida State League, and his chase rate ran in the 95th percentile for that specific Single-A circuit. However, only 8.6 percent of his batted balls were hit 95 mph or harder.
The Marlins knew they were throwing the young Venezuelan, who had time at six different positions in ‘25, in the deep end, and they believed his makeup and family history made him uniquely suited for the challenge. With that initial taste, their hope is Salas can be more physically ready to devour the lower Minors upon his return.
“He fought pretty hard and did a pretty good job of fighting,” Balkovec said. “He's put on 20 pounds since last year, and that's a credit to him and his makeup and his work in the offseason. I think that that was one thing he probably learned about the long season, and the toll it can take on his body. So he's coming in a lot more prepared this year from a physical standpoint.”
Something to prove: Noble Meyer (No. 15)
While White has become the face of the Marlins’ pitching group, another top 2023 Draft pick is looking to get back on track in ‘26.
Drafted 10th overall as an Oregon high schooler that year, Meyer hasn’t found the same level of success through his first two full seasons, partly because of health (sciatica in 2024, lower-body injury last year) and partly because his stuff slipped.
The 6-foot-5 right-hander posted a 4.41 ERA with 72 strikeouts and 38 walks in 65 1/3 innings for High-A Beloit last season. Perhaps the more worrying number was that his fastball velocity was only in the 90-93 mph range. Meyer’s extension from his size could still make that workable, but at a time when he was meant to fill up his 6-foot-5 frame, the loss of heat became a worrying trend. He worked with Driveline in the offseason to regain some of that velocity and posted on X on January 27 a video of him touching 98.6 mph.
Meyer’s low-80s slider drove his strikeout rate in 2025, but if he can blow the heater by a few more batters and hold this velocity into the summer, he could be right back on track entering his age-21 season.
“He’s another guy who’s done a tremendous amount of work in the offseason, physically and mentally,” Balkovec said. “Obviously, we saw a bit of a velo drop last year, and he has worked really hard in the offseason to address that.”
WBC standout: Owen Caissie (No. 3/MLB No. 42)
The Fish acquired Caissie from the Cubs back in January as the prospect headliner in the Edward Cabrera deal. He may have hit only .192 with one homer and a .568 OPS over the short 12-game sample in the bigs in 2025, but he also entered the organization with 982 plate appearances of experience at Triple-A dating back to 2024. He’d clubbed 41 homers over those two seasons in Iowa, proving that his power needed a new challenge in The Show.
That same trademark pop is what led him to Canada in this year’s World Baseball Classic, and he was one of the stars for his native land, hitting .412/.476/.765 with one homer and three doubles in five games as Canada headed to the quarterfinals for the first time in the event’s history. His 21 WBC plate appearances beat his 20 PA in the Grapefruit League, an oddity when he was competing for an Opening Day outfield job in his first Spring Training with his new org.
His new manager in Miami wasn’t concerned about Caissie getting in his work elsewhere, however.
“We knew what we had or thought we had coming into this,” said Clayton McCullough, “and him not being here -- and what he did -- didn't sway us one way or the other. I think if he had stayed in camp with us, it wouldn’t have done a whole lot either.”