3 NY Mets prospects who should be more untouchable than most realize

2) Jonathan Santucci

Another Mets pitching prospect that we could see by the end of 2026 is Jonthan Santucci. The 2024 second-round pick started the year at High-A Brooklyn, where he put up a solid 3.46 ERA, 3.63 FIP, and 1.26 WHIP over his first 67.2 innings of 2025. The left-hander struck out 26.4% of opponents, with an 8.1% walk rate, and a 0.93 HR/9 ratio. That earned Santucci a promotion to Double-A Binghamton, where his game completely took off from there.

His final 50 innings of the year yielded a 2.52 ERA, 2.43 FIP, and 1.02 WHIP. He was now striking out nearly a third of opponents, with a 32% K%. Santucci also became less home run prone, with a 0.36 HR/9 ratio. The only noteworthy number he didn’t improve upon was his walk rate, which rose to 9.1%, but was still better than the Eastern League league average mark of 10.1%.

It was only 50 innings and ten starts, but Santucci’s play at Double-A made him one of the best pitchers at that level. Among Double-A hurlers with at least ten games started, the Southpaw ranked 20th in ERA, 10th in FIP and K%-BB% (22.8%), 11th in strikeout rate, 16th in WHIP, and was one of only 14 pitchers to hold opponents to a batting average below the Mendoza Line, with a sub-0.50 HR/9 ratio. This was all in just his age-22 season.

Santucci’s fastball sits 92-96 MPH with outstanding carry through the strike zone, giving it the ‘rising’ fastball effect on batters. His low-80s slider is his best pitch, as MLB Pipeline projects it as a potential plus offering. Santucci’s second breaking pitch is a low-80s curveball that he began throwing this season. The lefty’s change-up is the only pitch in his arsenal that doesn’t project as above-average, but it’s still a usable offering that can throw hitters off. Like Watson, Santucci was a two-way player early in his college career, as he played some outfield, giving him good athleticism.

Santucci is the best left-handed pitching prospect in the Mets’ system. Baseball America recently ranked him as their tenth-best prospect on their updated top ten Mets prospect list. Given how well he pitched at Double-A, Santucci may open 2026 at Triple-A Syracuse, even if it was only after ten starts.