The Minor-League Star Who Could Become the Brewers' First Baseman in 2025

Coming into the 2024 season, most outlets projected Tyler Black as the incumbent to take over first base duties within the season. A player with capable range at third base, you would expect Black to provide plus defense if moved to first base, but that hasn’t been the case. Combine the defensive issues with a bat that has been solid but unspectacular (with mildly concerning exit velocities), and you can see why Black has struggled to force his way onto the Brewers' major-league roster.

He now has a big threat looming behind him, in the form of 6-foot-6, 250-pound first baseman Ernesto Martinez Jr. Strong bat-to-ball skills but a disappointing dearth of power defined Martinez's profile coming into the season, and even for the first few months of 2024 at Double-A Biloxi. Since then, however, he has leveled up into one of the most devastating power hitters in what is very much a pitcher-friendly environment. 

What Makes His Bat Stand Out?
Before stating some of the numbers produced by Martinez, absorb these baselines: Since Jul. 1, the average slash line in the Southern League is .235/.328/.356, with a 23.2% strikeout rate. Only six qualified players have an OPS over .770 in that span.

Martinez is leading the league in batting average and slugging, with a .349/.443/.558 line; a 13.9% strikeout rate; and an 11.4% walk rate in that period. He has 22 extra-base hits in 201 plate appearances, and added another home run in the first game of the Shuckers' playoff series against the Montgomery Biscuits. He’s recorded exit velocities of over 115 mph multiple times this season. This is a bat that has finally begun to uncork its destructive potential, with a 195 WRC+ in the second half.

Make no mistake, he was an above-average hitter even in the first few months of the season, but he’s cut down his pop-ups from 11.9% to 2.8% in the second half and the quality of contact overall has been incredibly consistent. His gigantic frame means the swing is naturally longer than most, and perhaps for comparison's sake, two members of the Yankees are appropriate. Giancarlo Stanton and Aaron Judge are large human beings with long levers, Stanton having an enormous swing path and bat speed to boot, while Judge has shortened his swing path so as to maintain a contact rate that Stanton struggles to match.

Both are in the top four swing lengths in all of baseball, and that puts a premium on early pitch recognition and adjustability in the swing. While no one is saying Martinez is either of these characters, and while he doesn’t quite do the same level of damage to the baseball, he's posted a better-than-average swinging strike rate of 10.6% and a contact rate of 77.2% since the start of July. For context, league averages in the Southern league are a 13.4% swinging strike rate and 72.1% contact rate.

Martinez’s intriguing blend of contact and occasional displays of massive power have come to a head over the last couple of weeks, with back-to-back Player of the Week honors in the Southern League. During that time, he’s belted two homers, four doubles and struck out on a measly three occasions. He’s shown improved pitch selection and recognition this season. That bodes well, for a player who’s Rule 5 Draft-eligible this offseason.

The Bonus Bits
There’s even more reason to be excited by Martinez. The Brewers have tried the giant Cuban out in center field, and although the experiment didn’t last, the speed and agility that prompted it shows up in other parts of his game. Martinez has 20 stolen bases this season, for the second time in his minor-league career--a large total for a player in that position--and has some of the best hands at first base I’ve seen in a while. He uses that frame and agility to cover a lot of ground around the bag. His ease stretching out is really quite obvious:

An excellent defensive first baseman, he’s the type of player who could contend for a roster spot in spring training if he shows out well, especially if Jake Bauers continues to struggle. As a left-handed batter, Martinez would marry well with Rhys Hoskins and provide that strong defense the Brewers are looking for.

There are still areas in which Martinez could access further power, to all fields. Tapping into that light-tower pull-side power could elevate his game further, and that (again) will come from pitch recognition and an awareness of how to access that 'A' swing. As things currently stand, he’s unlikely to hit 20-plus home runs in a season, unless he can consistently maintain those exit velocities on lofted balls. At 25 years old in Double A and coming toward Rule 5 eligibility, this was a big season for Martinez. It’s safe to say that, in one of the most difficult offensive environments in the minor leagues, he’s taken the forward step he needed. Whether the Brewers can unlock yet more from the large Cuban is another matter, but there are the raw tools of a star and the solid floor of a big-league player in his giant frame.