Fish On First Prospects Report: Why Fenwick Trimble continues to rise up Marlins prospect rankings

For the 2026 season, Fish On First will provide weekly reports on the Miami Marlins farm system, covering all levels. In case you missed it, our FOF Top 30 list has been updated to reflect takeaways from the first three months of minor league ball.

This report covers the games played from June 23-29.

Triple-A Jacksonville

A lot of the action for Jacksonville has been on the pitching side.

Brandon White, who was ranked No. 20 on the recently updated Fish On First Top 30, has had mixed results at the Triple-A level, posting a 6.07 ERA, 4.77 FIP, 11.53 K/9 and 1.82 BB/9. Although the surface numbers don't look great, White slider generates a 31.3% whiff rate. White is known for his phenomenal command, posting a career-low walk rate this season.

One of the biggest developments for White is his uptick in fastball velocity, averaging 95.3 mph at the Triple-A level compared to 91.3 mph two years earlier with Low-A Jupiter.

Between his last two starts, White has allowed one (unearned) run on three hits and struck out 18 hitters and only surrendered one walk.

Karson Milbrandt continues to succeed at the Triple-A level, but with the caveat that he is struggling with throwing strikes. He has walked three or more hitters in all four of his Jumbo Shrimp starts, most recently walking six against Memphis. Overall, Milbrandt has a 2.33 ERA, 4.23 FIP, 8.84 K/9 and 7.91 BB/9 in 19 ⅓ innings with Jacksonville. He is ranked sixth on the Fish On First Top 30.

Milbrandt's sweeper continues to be a strong weapon in his already expanded arsenal. He is generating 37.1% whiff rate with that pitch. In his most recent start, his final strikeout came on the sweeper. It has been his best pitch in terms of stuff plus.

Milbrandt's selection to the Futures Game should be made official by the end of the week.

Since the Marlins optioned reliever William Kempner, he has yet allow a run in five innings of work, striking out five, but also walking five. Kempner is eligible to be recalled beginning on Wednesday.

Double-A Pensacola

The Wahoos put their never-say-die attitude on full display this past week against the Lookouts, erasing early deficits multiple times to stork back and take four out of six games in the series. They erased a seven-run lead on Friday and a six-run lead on Saturday en route to improving to 40-35 on the season. Runs were plentiful for Pensacola who heads into this week having plated 12 runs in three straight games. They are also five games above .500 for the first time this year.

Over the course of the past few weeks, Cam Cannarella has been arguably the best hitter in Minor League Baseball. His breakout campaign continued at an astounding pace this series in which he went 7-for-24 with three more home runs, bringing his season total to eight including five already in 22 games at Double-A.

Cannarella continues to answer for questions surrounding his ability to hit for power in the most impressive ways. Not only has he put out the aforementioned eight homers, the way in which he has put most of them over the wall has stood out even more: Cannarella is frequenting the opposite field at a 42% rate. The power just adds another layer to already great skill set that includes plus-plus defense, good speed, and a budding 60-grade hit tool. This is about as well that an early-round Marlins’ draft pick has produced at the upper minors in recent memory. A debut next season is becoming more of a certainty by the day, especially as Jakob Marsee continues to struggle at the big league level.

Fenwick Trimble this past week turned an upward trajectory into the best series he’s had so far this season, earning himself Southern League Player of the Week honors. In the series, Trimble went 10-for-25 with a hit in every game. His best performance was a 4-for-6 effort in which he recorded 12 total bases and drove in a career high five runs.

Trimble showed tenacity through a tough start to the season and adjusted back to Double-A pitching very advantageously, one of the tougher tasks to accomplish in a young player’s career. His .281/.395/.500 June stands out both from a physical and mental standpoint. Even as the quality of stuff he’s faced has taken a jump, Trimble has stayed patient, worked counts and shown the ability to spray the ball to all fields. He had been a hit-over-power guy historically, but like Cannarella, the Marlins have helped him to tap into some more muscle. His 11 homers this season already top his 2025 total and his 17 doubles are two away from last year’s figure. What he lacks in raw strength Trimble makes up for with quick hands and a short swing which is what has spurred his power surge.

Defensively, Trimble can hold down all three outfield spots. Because of an average throwing arm and the Wahoos’ outfield depth he’s played more in the corners this year, but he will continue to be an easy player to get into everyday lineups. The epitome of a safe player with four of five tools, Trimble continues to rise up prospect rankings. He has a high floor and if the power persists, it will continue to rise. A Triple-A call-up could be in the cards in pretty short order. Trimble is proving he was a nice find by the Marlins in the fourth round of the 2024 draft.

High-A Beloit

The Sky Carp were the beneficiaries of some solid pitching performances in their series against the Peoria Chiefs, allowing them to split a six game set despite scoring less than four runs a game on average. They exacted revenge against Peoria who swept them on the road earlier this month.

The stuff profile has always been there for Carson Laws, the Marlins’ 14th-rounder from this past year. The issue for Laws lately has been getting his command to persist, which is what led to him allowing 17 runs through his previous three outings which lasted just a combined 10 ⅓ innings. On Wednesday against Peoria, though, Laws showed what he is capable of when his stuff is working at its best: the 6’1”, 186-pounder tossed the first quality start of his career while striking out a career high nine Chiefs. The only blemish on his line was a single walk.

It had been a fairly rough start to Laws’ transition from bullpen work to starting. Even after this spectacular outing, his ERA on the season is still over seven. Laws rewarded the Marlins’ confidence in trusting in his ability to be stretched out with this fantastic building-block outing. With just average size, Laws isn’t the Marlins’ archetype arm but he has the ability to ramp up velocity and he flashes high spin rates with deceptive movement over all three pitches, giving him the capacity to fool hitters. For Laws, who spent the offseason in an effort to hit 99 mph, harnessing command and control in order to continue to last multiple innings consistently will be what to watch for as his season progresses. Given his background, there is extreme reliever risk here limiting his ceiling, but you can see the vision the Marlins are trying to build towards. Because of his stuff, Laws has the makings of a potential high-leverage bullpen option.

Speaking of high-leverage relievers, the Marlins definitely have one in Justin Storm. The 24-year-old continued to dominate High-A hitters this week, as he got into three games and only allowed two hits in a combined four innings. On Sunday, he recorded his fourth save in five opportunities. His ERA has not been higher than 3.00 since May 13.

Storm is everything the Marlins love in an arm: size, stuff and nasty strikes. At 6’7”, 232, he’s one of the tallest pitchers in all of minor league baseball. Planing downhill from his extremely high lefty arm slot and from an extremely shortened distance to the plate, he’s very difficult to pick up. Storm features a nasty fastball/slider combo that was touted as one of the best in the country when he was drafted in 2023. When he has full control of his extremely long levers, Storm is deadly. He does need to show that control a bit more consistently as he’s shown a penchant for missing very far out of the zone on occasion, leading to a low O-swing and middle-of-the-road walk rate especially as he gets an opportunity against more advanced hitters, but if he can solve for that, Storm has a considerable ceiling as a high-leverage arm. At 24, he’s very old for High-A. The challenge to Double-A needs to come soon for him.

Low-A Jupiter

Things were looking bleak for Echedry Vargas just a couple months ago. Playing down a level from where he was in 2025, the 21-year-old was mostly being deployed at first base while not providing any of the power typically expected from that position. Two weeks away from game action in early May has helped him recalibrate. Vargas homered again in Jupiter's last series, raising his slugging percentage to .492—that would rank fourth in the Florida State League if he had enough playing time to qualify. Meanwhile, he's receiving more of an opportunity to demonstrate his defensive versatility, including a start at shortstop on Wednesday.

In his first series with the Hammerheads, Luis León went 4-for-15 with a grand slam. He got defensive reps at second base, left field and right field.

The Marlins have spent nearly half a decade attempting to develop right-hander Walin Castillo as a starter, but their patience may be running out soon. He surrendered a career-high 10 earned runs in his last outing. An ERA that stood at 1.37 in mid-May has nearly quadrupled since then to 5.12.

FCL Marlins

FOF's No. 15 prospect, Andrew Salas, had an excellent week. He he went 5-for-10 (.500) with another multi-home run game, his second of the year. Salas is still just 18 years old until next March, and the potential has been on display on numerous occasions this season.

We have already seen Luis Arana, Luis Cova, and Edgardo De Leon earn promotions after dominating the FCL to begin the season. Breyias Dean should be next. On the year, Dean is hitting .326 with four home runs, 26 RBIs, and has walked 18 times compared to just 25 strikeouts. As mentioned last week, with the MLB Draft approaching, the opportunity for promotions is opening up as organizations need roster spots for incoming draft picks. Dean is at the top of the list when it comes to players who have earned a promotion.

Juan Alva is right there with Dean statistically A career .325 hitter, Alva is batting .329 this season with three home runs, 16 RBIs, 12 stolen bases, and an impressive 23 walks compared to just 14 strikeouts. This past week he went 4-for-11 (.364), with all four of his hits coming across two multi-hit performances.

DSL Marlins & DSL Miami

David Shirley was with the DSL Marlins until this week before being transferred to DSL Miami. Prior to the move, he was hitting .333 in 36 at-bats, and the change of scenery did nothing to slow him down. Shirley went 6-for-15 (.400) this week with multiple multi-hit games, three RBIs, and two stolen bases. He has continued to put together quality at-bats and has been one of the hotter hitters in the organization over the past couple of weeks.

José Rosal made just one appearance this week, tossing two innings while allowing two hits, walking three, and striking out three. On the season, he owns a 0.87 ERA (1 ER) across 10⅓innings. The biggest concern has been his command, as he has issued 12 walks compared to just eight strikeouts, contributing to a 1.84 WHIP. Despite that, Rosal has consistently found ways to escape trouble and limit damage, which has allowed him to keep runs off the board.

After a rough first three outings to start the season, Keyner Cedeño has been nearly unhittable over his last four appearances. Across his last 10 ⅓ innings, he has struck out a whopping 22 hitters while issuing just three walks. This week alone, he threw 6 ⅔ innings and struck out 13 batters. The stuff has always been there, and it looks like Cedeño has figured something out over the last couple of weeks.

Stiveen Rojas got off to a slow start this season but has picked things up lately. On Monday afternoon, he struck out eight over 4 ⅓ innings. Overall this week, he recorded 10 strikeouts across 6⅓ innings while allowing just one run. The biggest issue continues to be the walks, as he has now issued 18 walks while striking out 18 hitters. Opponents are batting just .167 against him, but his 1.59 WHIP shows how much the free passes have hurt him.

There is no other way to put it—Daniel Pire has been the best-performing player from the Marlins' 2025 international free agent class. This week he went 5-for-11 (.455), highlighted by a game in which he collected three doubles and drove in three runs. On the season, he is hitting .333 in 60 at-bats and has walked more times (9) than he has struck out (7). His approach at the plate has been one of the most impressive in the DSL.

Bayant Melo is now in his fourth season in the DSL, and this has been his best year by far. Across 15 ⅓ innings, he has recorded 16 strikeouts. The walks are still an issue, but the results are finally beginning to match the quality of his stuff. This week he tossed three scoreless innings, striking out three while walking two and hitting a batter. His season ERA now sits at 2.35. At 21 years old, this is a make-or-break season.

Yerison Mendez has had one of the stranger statistical seasons in the organization. He owns a 2.03 ERA across 13⅓ innings but has a 1.58 WHIP. He has walked nine batters while striking out just six. This week, he threw four scoreless innings, allowing four hits, walking three, and striking out none. So far the results have been on Mendez's side, but it has been a very unusual season to this point.

This week's schedule

• Triple-A Jacksonville at Nashville
• Double-A Pensacola at Rocket City
• High-A Beloit vs. South Bend
• Low-A Jupiter vs. Dunedin
• FCL Marlins, DSL Marlins and DSL Miami vs. various opponents

Interested in learning more about the Miami Marlins' top prospects? Check out our comprehensive top prospects list that includes up-to-date stats, articles and videos about every prospect, scouting reports, and more!