Is this 97 mph-pumping 18-year-old the next Red Sox top pitching prospect?
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It’s tremendously difficult to make the International Top 50 Prospects list any given year as a pitcher. With the majority of players 16 or 17 years old, hurlers just don't have the same track record as position players, and those who ply their trade on the mound have only begun to do so full time on a fairly regular basis.
But Sadbiel Delzine has long been made from a different mold.
One of just four hurlers to land on MLB Pipeline's 2025 International Top 50 list, the Red Sox brought Delzine aboard with a $500,000 signing bonus, the most they had paid to an international hurler in nearly six years (since Chih-Jung Liu in 2019). Despite dealing with a mild flexor strain and working just 9 1/3 innings across three outings in the Dominican Summer League that year, the organization sent him stateside in 2026 as an 18-year-old.
Delzine, now the Red Sox No. 7 prospect, largely overpowered Florida Complex League hitters this summer, holding opposing batters to a .170 average and a .199 slugging percentage-against. In his 11 outings (39 2/3 innings), he yielded just four extra-base hits, all doubles. He got the bump to Single-A Salem in late July and has continued to stack up strikeouts with 30 in 21 innings against Carolina League competition.
Overall, Delzine is one of just four pitchers 18 or younger to toss 60+ innings this season across the Minors. His 2.82 ERA across the two levels is the best among hurlers currently in the Red Sox system (min. 60 IP) and his .185 average-against and 3.49 FIP rank within the top three as well.
Delzine has made significant velocity jumps since joining the Red Sox organization. Clocked at 93 mph as an amateur, he has since added good weight to his 6-foot-5 frame and dialed his heater up around 96-97 mph consistently in both the FCL and in his recent outings for Salem. His 60-grade fastball already puts him in rare company as he pairs it with three plus secondary offerings (changeup, curveball, slider), making him one of just six ranked prospects in all of baseball to meet those thresholds.
The advent of a second breaking ball has made Delzine a menace to left-handed batters in particular. He’s run reverse splits this summer, holding opposite-side hitters to a .154/.273/.173 slash line, allowing just two extra-base hits (doubles) in 122 plate appearances. His mid-80s slide piece has some cutter shape to it and his upper-70s/low-80s curveball falls off the table from a high three-quarter slot, often leaving batters whiffing over the top of it.
The book on Delzine coming out of his native Venezuela was that, despite his size, he possessed exemplary command. He backed that up in his brief DSL stint, walking just one of the 39 batters he faced. Even during his stateside debut this year, he has run a walk rate below 10 percent (9.6), making him one of just 37 pitchers across the Minors to pair that mark with a K rate above 29 percent (29.1). (Nine members of that group are currently ranked on MLB Pipeline’s Top 100 Prospects list.)
Delzine’s command has improved as the season has gone along, and he's walked just a combined two batters over his past four starts. The Red Sox have kept his pitch count in check, not allowing him to exceed 63 in any of his six outings for Salem.
Not since the days of Brayan Bello have the Red Sox had an international pitching prospect with a full complement of raw stuff. It's still early in Delzine's development, but he has all the makings of a future starter who could make an impact at Fenway.