Marlins Prospects Fall 7-6 in Tight Spring Breakout Showcase Game

Marlins No. 10 prospect Karson Milbrandt struck out six Astros prospects over three hitless innings at West Palm Beach's CACTI Park of the Palm Beaches, but a bullpen collapse turned a commanding advantage into heartbreak. The Marlins' early lead held until the bottom of the ninth, when Cannon Pickell walked two and allowed a single to load the bases for Caden Powell, who walked it off for the Astros. The final score: 7-6.

For the first time since the inception of MLB's Spring Breakout prospect showcase, the Miami Marlins had to leave the friendly confines of Roger Dean Chevrolet Stadium, their top farmhands traveling 15 minutes south to West Palm Beach on Thursday afternoon to face the Houston Astros prospects. In the third annual prospect showcase, the Marlins tabbed Milbrandt to start following back-to-back years of Thomas White doing so. White, who ranks as MLB Pipeline's No. 17 overall prospect, is rehabbing from a Grade 1 right oblique strain. Miami had also reassigned Robby Snelling, MLB Pipeline's No. 39 overall prospect, to Minor League camp on Wednesday after an impressive big league camp.

Milbrandt, who turns 22 on April 21, was more than worthy of filling in for that pair. His final line — three innings, no hits, one run, three walks, six strikeouts on 54 pitches — understated how electric his stuff played. His fastball topped out at 97.1 mph and averaged 95.6 mph, and he executed his strategy perfectly, elevating heaters and burying his breaking stuff, including his relatively new gyro slider, which he developed quickly last season and has emerged as his best pitch. The slider generated five whiffs and recorded three strikeouts, with his first slider strikeout victim being Astros No. 5 prospect Walker Janek. Baseball America noted he "generated the second-most swings and misses (12) of any pitcher in Spring Breakout."

The one blemish on Milbrandt's outing came not from a hit but from a run-scoring wild pitch, which accounted for the only damage during his three frames. He acknowledged the mixed result afterward with characteristic self-assessment.

"They told me about two, three weeks ago that I [was] built up for three, that I'll be starting this," Milbrandt said. "Some good, some bad. Obviously, three walks, not good, but six punchies is good. Still working on the feel stuff."

On the slider specifically, Milbrandt pointed to feel as the primary work-in-progress: "It's quickly become one of my favorite pitches," he said. "I like to throw it a lot. Today the feel was a little bit off, but the movement was good, so looking forward to getting that pat down."

Marlins director of player development Rachel Balkovec noted the organization's confidence in Milbrandt's development arc, and he carried a strong Arizona Fall League showing into this spring, earning Fall Star designation with a 15.5 K/9 rate. That trajectory built on a 2025 breakout with High-A Beloit where, as a non-roster invitee at big league camp, he tossed two scoreless Grapefruit League innings with one hit allowed, three strikeouts and no walks before earning his Spring Breakout start. His 2025 Sky Carp line was equally striking: command will be key moving forward, though his walk percentage marginally dropped from 13 to 12.3 in 2025.

While Milbrandt was dominant early, the Marlins built their lead the old-fashioned way in the middle innings. Kemp Alderman, starting at designated hitter, went 2-for-3, with one single clocked at 87.4 mph exit velocity into center field. He then extended the Marlins' lead to 6-1 with a two-run single to left field in the top of the fourth, plating Starlyn Caba and Dillon Lewis. Alderman will be a name to follow closely as he starts the season with Triple-A Jacksonville, coming off a 2025 campaign where he slashed .285/.338/.482 with 22 home runs, 70 RBI, and 22 stolen bases across Double-A and Triple-A, earning 2025 Marlins Minor League Player of the Year honors.

Aiden May stranded the bases loaded in both of his innings, and the Marlins also stranded the tying run in scoring position in the eighth before Powell's bases-loaded walk ended it.

Acting manager Jeff Conine, a Marlins Legends Hall of Famer serving as a special assistant to the club, summed it up plainly after the game: "This is the future of our organization. They are a bunch of good kids, work hard and I think on the pitching side we just didn't have it today in the strike zone, but we gave them a good effort."

Milbrandt's outing reinforced what scouts saw coming: a right-hander with a mid-90s fastball and a slider that, when located, gives hitters nothing to square up. Balkovec described a transformed version of the pitcher the organization has watched develop: "He's more confident. He just kind of walks in the room and he knows the work that he's put in. And you can feel it, you can hear it. You can hear how he's talking. Again, just offseason preparation, his physicality and his confidence in trying new things." For Miami, the walk-off loss stings, but Milbrandt's three innings pointed toward a 2026 season where the organizational pitching pipeline begins cashing in on its investment.