Too often, the evaluation of a baseball prospect fluctuates dramatically based on their most recent season. Fish On First is occasionally guilty of this, with Miami Marlins first baseman Deyvison De Los Santos being a prime example.

At this time a year ago, De Los Santos ranked third on the FOF Top 30 as Minor League Baseball’s reigning home run king. Currently, fresh off a disappointing season at Triple-A, he is ranked 23rd. That’s in large part because his surface-level production cratered, from 40 homers and a 127 wRC+ in 2024 to 12 homers and an 84 wRC+ in 2025.

But under the hood, nothing about De Los Santos’ player profile fundamentally changed. He possesses plus-plus power—in both seasons, his 90th-percentile exit velocity was 108 mph (for reference, Agustín Ramírez is at 109 mph). His chase rate against Triple-A pitching actually improved from 45.0% to 35.0%, though that is still a concerningly high figure. It’s been obvious throughout this period that first base will be his long-term defensive home. Despite shattering his previous career-high with 16 stolen bases in 2025, he remains a below-average runner by MLB standards.

De Los Santos did not do enough to earn a call-up from the Marlins last season. He also did not disqualify himself as a potential reinforcement further down the road. He’s only 22 years old!

Between a quad injury and travel issues, De Los Santos had fewer MiLB reps than hoped (106 games in AAA). He is compensating for that now in the Dominican Winter League (LIDOM), where he’s been starring for Gigantes del Cibao.

De Los Santos enters Monday ranked fourth among all qualified LIDOM hitters in both batting average (.351) and OPS (.892). He is in the midst of a 16-game on-base streak. Every single pitcher he’s faced is older than him and more than half of his plate appearances have come against guys who have MLB experience.

It has been a mixed bag for De Los Santos from a plate discipline standpoint. He has drawn only three walks through a full month of action and he occasionally gives away strikes at times by blindly guessing in favorable counts and swinging over the top of breaking balls. On the other hand, it’s encouraging to see him dial back his aggressiveness, offering at 30% of first pitches (roughly MLB average).

With few exceptions, the arms who have elite stuff and command are resting at this time of year. There’s only so much that De Los Santos can “prove” about himself against this quality of competition. The correlation between LIDOM run production and big league readiness is practically non-existent, as detailed in the table below.

OPS Rank

2020-21 LIDOM Season

2021-22 LIDOM Season

2022-23 LIDOM Season

2023-24 LIDOM Season

2024-25 LIDOM Season

1

Ronald Guzmán

Junior Lake

Henry Urrutia

Ronny Simón

J.C. Escarra

2

Joe Dunand

Leody Taveras

Ronny Mauricio

Franmil Reyes

Aderlin Rodríguez

3

Yamaico Navarro

Hanser Alberto

Aneury Tavárez

Mel Rojas Jr.

Jerar Encarnación

4

Junior Lake

Sócrates Brito

Ramón Hernández

Héctor Rodríguez

Sergio Alcántara

5

Jeremy Peña

Zoilo Almonte

Rainer Nuñez

Starlin Castro

Erick Mejía

 

 

 

 

 

 

 

Total MLB fWAR in 2021

Total MLB fWAR in 2022

Total MLB fWAR in 2023

Total MLB fWAR in 2024

Total MLB fWAR in 2025

 

-0.2

0.9

0.3

0.0

0.5

The Marlins are exploring opportunities to acquire a veteran first baseman, but they don’t feel obligated to do so if the value isn’t reasonable. FOF’s Isaac Azout and Kevin Barral report that they could patch things together with a combination of internal options such as Eric Wagaman, Connor Norby, Graham Pauley and Liam Hicks. Even if De Los Santos homered on a daily basis for the rest of the LIDOM season, the Marlins would still plan on sending him back down to Jacksonville to validate that he has turned a corner.

I have been pounding the drum as much as anybody for the Marlins to invest in their roster and first base was a glaring weakness for the Fish last year. That being said, they should be setting the bar very high and/or prioritizing first basemen with the flexibility to play additional positions. De Los Santos is a fascinating depth piece for 2026 who shouldn’t be ignored. If the Marlins have to block his path to the majors because they’ve added one of MLB’s best bats via trade or free agency, that’d be wonderful, but don’t spend money for the sake of spending money and bury him on the depth chart behind a low-probability bounce-back candidate.