Can a Dark Horse Push Aside Tyler Black and Jake Bauers for Backup Brewers First Baseman?

Ernesto Martinez Jr. hasn’t popped up on many prospect lists. He’s taken some time to live up to the potential in his frame, since signing with the Brewers out of his native Cuba. He passed through the Rule 5 Draft, unselected. He's become a minor-league free agent and re-signed with the Brewers, meaning no other team offered him even a 40-man roster spot.

And yet, the man possesses some of the most freakish upside in camp this spring. Perhaps you’ve heard Joseph Zarr raving about his athleticism at first base, regularly including doing the splits to snag a throw faster on a close play. He’s covered center field admirably in the past. He’s 6-foot-7 and weighs 250 pounds. Then you see what he managed to put together in the final half of 2024, in the tough hitting environment that is the Southern League, not just in raw power but with a complete performance at the plate.

To put what I’m about to say in context, you need to know just how horrible the hitting environment is. Here’s how Martinez Jr compared to the league average, examining both his full-season numbers, and his final three months:

Those surface stats mean something, but they don’t tell the whole story, either. Martinez’s frame has historically created issues for hitters in controlling the strike zone and making strong contact. Giancarlo Stanton is a prime example; the long levers he possesses allow him to create massive bat speeds. Unfortunately, it comes with prolific in-zone swing-and-miss. Martinez somehow has the wham, without the whiff—at least in the minors.

His 90th-percentile exit velocity for the Biloxi Shuckers last season was 109 mph. He repeatedly topped 115 mph on individual batted balls. Note in the below quote to Adam McCalvy that the blast motion sensors top out at 89.9 mph of swing speed:

“He tops out the Blast sensor when we use it,” [Brewers hitting coordinator Brenton] Del Chiaro said. “He’s just continued to impact the baseball. The ‘damage’ components, the quality of contact components, have continued to improve. He’s progressively gotten better the more he’s matured. You come to the ballpark, you’re going to see him do something special, whether it’s the full-on splits, whether it’s stealing a bunch of bases, whether it’s hitting the ball out of the ballpark. It’s going to be entertaining.”

What does this mean? Well, Stanton had far and away the greatest bat speed in the majors in 2024, averaging 81.3 mph, while exceeding 88 mph on his swings just 15 times. Martinez has shown himself capable of matching that while retaining a strikeout rate (in the worst hitting environment in minor league baseball) under 14%. Excited yet?

When you have a frame as large as Martinez (who is also affectionately nicknamed “the show” and “the Cuban missile”) does, it takes time to work out how to synchronize the mechanics of your operations in the box. It seems that’s finally happened for the Brewers' talented infielder, and his ceiling is sky-high. He's hitting fewer infield fly balls and more line drives, while simultaneously tapping into more pull-side fly balls than in previous seasons. All of this fits the description of a player becoming more aware of how to create damage and more in-tune with his bat path.

I am incredibly excited to see how this young man performs in 2025. With better defensive chops than both Jake Bauers and Tyler Black, alongside a higher ceiling and the stolen base threat, there's a real chance that Martinez is on the Brewers roster on Opening Day. It's more likely the Brewers will try those ahead of him in the pecking order first—particularly Bauers, who may have an opt-out on his minor-league deal if he isn't on the roster—so perhaps midseason is a more realistic goal for "El Espectaculo". Still, he has every chance to force their hand with a great Cactus League showing.