Marlins Fans Should Be Excited About Thomas White

The left-hander has had quite the ascension just this season alone. He’s now getting ready to debut for a third team in the Marlins system after having started the year with High-A Beloit.

Across the two levels where he has pitched so far, White has a 2.13 ERA, a 14.3 K/9, and a 42.2% groundball rate. He has allowed just two home runs across 80.1 innings pitched. The lefty has been able to execute his four-pitch arsenal with ease, which is quite impressive considering he is only 20 years old.

A Steal in the Draft

The Marlins selected Thomas White with the 35th overall pick in the 2023 MLB Draft. White being selected at 35 was a surprise to many, but maybe not for the reason you might think.

Heading into the draft, not only was White considered one of the best left-handed pitching prospects in the class, but he was consistently ranked as one of the best overall pitching prospects in 2023.

The fact that he landed in the Marlins’ laps at pick 35 led a lot of evaluators to quickly label him a steal in the draft. One factor that could have had teams a little skeptical was his commitment to Vanderbilt and potential signability concerns.

That was not an issue for the Marlins, who were quick to pry him away from his Vandy commitment with a $4.1 million signing bonus.

From the very beginning of the process, White was lauded for how clean his mechanics were for someone as young as he was. The delivery was repeatable, low effort, and efficient throughout the whole motion. His fastball was sitting in the low-90s at the time, topping out as high as 97, with a high average IVB (induced vertical break) of 23 inches that gave his fastball “life.”

Aside from the fastball, he had a tight slider that was spinning at around 2700-2800 rpm consistently and possessed up to 16 inches of horizontal sweep across the plate. He had such a good feel for this pitch that he was able to manipulate the shape, when asked, into more of a curveball.

Though he didn’t throw it as often, the curveball still flashed as a plus pitch. While he was also able to flash a good changeup during his showcase, it was not a pitch he threw often at the time. Yet, in the few times he threw it, the pitch sat in the low-80s and showed enough promise for scouts to believe it was going to give him a strong three-pitch mix at the professional level.

Well, the scouts were right.

White’s Professional Development

Much has been made about the Marlins’ pitching development over the past couple of years. From top to bottom, it always seemed as if there were a handful of new arms that would pop up on the radars of talent evaluators each season.

Many could say that White landed in one of the better situations he could have, in terms of pitching development. However, it was not until this last offseason that we saw POBO Peter Bendix complete his overhaul of the Marlins personnel throughout the entire organization.

It started back on November 10, 2024, when the Marlins announced the hiring of former Angels pitching coach, Bill Hezel, as their new director of pitching. That was when the new organizational pitching philosophy was implemented.

Prior to his time with the Angels, Hezel spent five years working at Driveline in a multitude of roles, including serving as their director of pitching for two years (2020-22).

The philosophy he brought over was simple: improve clarity from the major leagues all the way down to the Dominican Summer League and establish a clear and transparent plan to leverage the strengths of every pitcher to help them get ahead in counts, improve overall strikeout numbers, and properly execute when needed.

Simple enough, right? Well, it has certainly worked so far.

Especially for Thomas White.

Coming into this season, White had done a good job of building on the three-pitch mix that had him labeled as one of the best arms of his class. It was the implementation of this philosophy that helped him take it to the next level. It also aided in the development of not only a fourth pitch that he was able to throw comfortably, but a four-pitch arsenal of above-average pitches.

White attributes all of this development to the increased usage of analytics that the organization’s player development team has provided him with.

In 2025, he has been able to ramp his fastball velocity to as high as 98 mph without losing the high carry numbers he had before. The fastball is the first plus pitch he has. Next is the changeup that has become his second plus pitch to go along with the curveball and slider that get opponents out at equally high marks.

The sweeping curve is getting around 14 inches of horizontal break, while the slider is still sitting around the 17-to-18-inch mark, but it is the changeup that should have all pitching enthusiasts excited for whenever it is he makes his debut at the major league level.

The mid-80s changeup continues to be his go-to out pitch in any situation. Considering that it mirrors his fastball as well as it does, and the ease with which he can execute it, it is arguably one of the best pitches in the minor leagues today.

Needless to say, Thomas White looks to be as real a deal as a top-end pitching prospect can be.

What’s Next?

White’s promotion comes on the tails of his going 2-0 in his last five starts in August with a 1.07 ERA, 42 strikeouts, and an opponents’ batting average of .174 across 25.1 innings pitched.

He has made two starts this year where he eclipsed the 10-strikeout mark, the highest being his five-inning, 14-strikeout performance on July 26.

The 20-year-old left-hander looks primed to be one of the next exciting arms to make his debut in the major leagues. While it may not be until around the All-Star break in 2026, there will be plenty of opportunities for fans to see him throw against major league competition during spring training next year, where he is likely going to get a chance to pitch for the big league club.