Marlins pitching prospect Yohanfer Santana undergoes Tommy John surgery

Miami Marlins right-handed pitcher Yohanfer Santana recently underwent Tommy John surgery, Fish On First has learned. 

A native of San Pedro de Macoris, Dominican Republic, Santana signed an international free agent deal with the Marlins in 2023. His production in the Dominican Summer League over the last two seasons has been unremarkable on the surface: 31.1 IP, 7.76 ERA, 7.63 FIP, 1.95 WHIP in 13 G/10 GS. He was not included in our recent Fish On First Top 30 update.

However, Eric Longenhagen explained on FanGraphs in June why the 18-year-old has immense upside:

He’s built like an NBA small forward prospect at a broad-shouldered and skinny 6-foot-7, and he shows feel for three pitches. Santana’s low-90s fastball of 2023 had promising vertical ride, while his upper-70s curveball flashed the sort of depth that should play nicely with that kind of fastball, though it needed more power. At the end of the season, it felt very likely that Santana would develop immense arm strength as he matured. He has so much room for mass on his frame and his arm action is so clean and fluid — this seemed like the type of pitcher who could end up throwing 100 one day. All of that was projection, of course, based purely on visual assessment.

In his first DSL start of 2024, Santana sat 93-98, debuted a slider/cutter in the 88-90 mph range and was working with a 91-94 mph changeup. Were he in the draft, he’d probably go in the mid-to-late first round and get a bonus approaching $3 million. This is a very exciting, uber-projectable 18-year-old who is in the midst of a velocity surge.

The DSL start that Longenhagen references took place on June 4. Santana pitched again on June 11 and dominated (3.0 IP, 0 H, 0 R, 1 BB, 7 K). The following outing on June 18 was a rough one, though (2.0 IP, 3 H, 5 ER, 2 BB, 2 K). The Marlins placed Santana on the 60-day injured list on June 25, ending his 2024 season. Soon after, he traveled to the United States to undergo surgery. He's currently rehabbing in South Florida.

Barring setbacks, it takes most pitchers 12-18 months from their TJ surgery date to return to game action. MLB prospects are understandably handled cautiously and usually fall on the high end of that range. Santana is not expected to appear in another minor league game until 2026.

The FOF injury/rehab tracker will provide regular updates on Santana's progress.

Interested in learning more about the Miami Marlins' top prospects? Check out our comprehensive top prospects list that includes up-to-date stats, articles and videos about every prospect, scouting reports, and more!