A general view hats belonging to Chicago Cubs players in the dugout during the first inning during a spring training game against the San Fracisco Giants at Scottsdale Stadium. Allan Henry-Imagn Images

Cubs Prospect Became Velocity King of Minor League Baseball in 2025

Originally posted on Chicago Cubs on SI | By Matt Postins | Last updated Oct 27, 2025 9:00 AM ET

Major League prospects are chasing velocity every year. Coaching staffs are helping those prospects try to get every last bit out of each pitch.

The Chicago Cubs are no different. In the past few years, the system has produced quality arms, including two first-round picks in Jordan Wicks and Cade Horton. While Wicks hasn’t been able to maintain the momentum of his rookie year, Horton looks like he could be as high as the No. 2 starter in next year’s rotation.

Recently, Baseball America (subscription required) compiled every minor league prospect that saw a two mile-per-hour jump in their fastball speed from 2024 to 2025. The only requirement was that the pitcher had to throw at least 100 fastballs in 2025. The idea was to see which prospects improved their velocity with baseball’s core pitch.

The Cubs had one player make the list. In fact, that prospect was at the top of the list.

Matt Marton-Imagn Images

Jostin Florentino, Velocity King

Cubs prospect Joston Florentino threw a top-line fastball of 84.9 mph in 2024. In his first year stateside, his fastball exploded. It went up to 90 mph, a change of 5.1 mph. He was the only prospect to see a change of five mph or more year-over-year.

It was so startling that Baseball America’s Geoff Pontes had to provide a note for context.

“In addition to having one of the best sliders in the minors, the 20-year-old right-hander gained over 5 mph on his fastball this season to top the list,” Pontes wrote. “His velocity is still below-average, but his results took a significant jump in 2025.”

Anything for you, CubsWRLD. Admin enjoys watching Jostin Florentino pitch... that sweeper pic.twitter.com/zlXGUtUdGA
— Myrtle Beach Pelicans (@Pelicanbaseball) August 2, 2025

Yes, a 90 mph fastball is unlikely to play well in the Majors. But with a quality slider, it gives him a two-pitch mix that could allow him to rise through the system as a reliever, especially if the fastball velocity continues to increase.

For now, the Cubs are treating him like a starter. He began 2025 with the Arizona Complex League Cubs and was later promoted to Class-A Myrtle Beach. He combined to 5-5 with a 2.43 ERA in 16 games (14 starts). He struck out 101 and walked 25 in 81.1 innings while batters hit .201 against him. A promotion to High-A South Bend next year isn’t out of the question.

The Cubs signed Florentino as an international free agent in 2023, and they assigned the Dominican Republic native to the Dominican Summer League, which is customary for teenage international signees. His first year in the DSL saw him go 4-1 with a 3.57 ERA in 13 games, all in relief. He struck out 35 and walked 10 in 35.1 innings.

He stayed in the DSL in 2024, and his record dropped to 1-2. But so did his ERA, which was 2.06. He started seven of his 10 appearances. He struck out 40 and walked 10 in 35 innings. Also of note was his opponent's batting average dropping from 2023 (.256) to 2024 (.167).

Will They Stay Or Go? The Chances Of Every Cubs Free Agent Returning

3 Key Offseason Moves The Cubs Must Make To Return To The Postseason

Cubs Face Crucial Decision On Shota Imanaga’s Contract — Breaking Down The Options

MLB Insider Names Intriguing Free Agent Fit For Cubs

This article first appeared on Chicago Cubs on SI and was syndicated with permission.

More must-reads: