In MLB, few teams have the level of young pitching that the Boston Red Sox currently possess. There’s Connelly Early, who debuted in 2025 and had a strong showing in 4 games, posting a 2.33 ERA with 4 walks and 20 strikeouts in 19.1 innings. After a strong 2026 spring training, Early cracked the rotation and blossomed, with a very similar 2.29 ERA in 19.2 innings across 4 games as well.
Then there’s Payton Tolle, who currently sits atop the SoxProspects prospect board, and after a rough major league stint in 2025, is currently in AAA Worcester, working on his secondaries, to cash in on his otherworldly potential. If that’s not enough, just look at the 2025 draft class. With the 15th overall pick, they selected Kyson Witherspoon from Oklahoma, who features an upper-90s fastball, a deep curve, a cutter, and a solid changeup and slider. He’s struggled to a 6.14 ERA in 2 games at High-A Greenville but shows plenty of promise. Then, there’s third round pick Anthony Eyanson out of Louisiana, who’s dominated at Greenville, having posted a 1.23 ERA and 0.41 WHIP over 7.1 IP, for two games.
But the best of the group may be hiding right under our noses. That would be 18-year-old Venezuelan righty Sadbiel Delzine. Delzine was signed in the January 2025 signing period and was given a $500,000 bonus, which was the 4th highest overall, behind Eliezer Alfonzo ($700,000), Harold Rivas ($900,000), and Dorian Soto ($1,400,000). Delzine also had the highest bonus given to a pitcher in that class, and the highest since 2019, with the only pitcher higher being righty Chih-Jung Liu, who signed out of Taiwan for $750,000 in October 2019.
Sadbiel Delzine. Source- https://www.instagram.com/iam_delzine/
Right now, the verdict on Delzine is looking strong, but rightly cautious. He features a plus fastball, which is now sitting around 94-97, while topping at 98, according to Fangraphs most recent report. Both Fangraphs and MLB Pipeline also love his secondaries, with Pipeline giving him a 55-grade curveball, which Fangraphs says may just be a slider, where they gave him a potential 60 grade. Pipeline says the slider is a separate pitch, and they give him a 55. Pipeline likes the changeup more than Fangraphs, but both agree it should be around average.
The good thing about Delzine is that his command should be average, which will allow his pitches to play up. The big pitch is the fastball, as it already has plus velocity, but with Delzine being 6’5”, 198 lbs, it could easily increase as he gets larger, which makes his ceiling quite high, as he’s already very strong and well-built for his size. That, plus the low to mid-80s breaking balls, have plenty of movement and will also improve as he matures.
Even with all that upside, he still carries considerable risk, given the fact that he’s only a teenager and that he’s also only pitched in three career games. In those three games, Delzine did get hit up, posting a 4.82 ERA and a .297 opposing batting average in 9.1 innings, before being shut down with a flexor strain. That means that he’ll have to stay healthy and build up a workload if he wants to hit his ceiling of a dominant MLB starter. Although he got hit around, opponents posted a .393 BABIP against Delzine, which means they got more hits than they likely should have.
Those numbers don’t tell the whole story, however, as Delzine actually limited major results quite well. He put up a 64.3 GB% and allowed no home runs, which showed that those hits likely weren’t well-hit baseballs. Furthermore, batters were only making contact on just under 55 percent of pitches, which is well below the MLB average, showing how good his stuff is. That rate should increase as he faces higher-level competition, which he should in 2026, as a move stateside is in the cards. Delzine also exhibited elite control, only walking 1 of 39 total batters faced. The strikeouts also came in at a good clip, as he averaged a punchout per inning. That means that Delzine just got unlucky, as the limited quality contact, low walks, and high strikeout totals put his FIP at an elite 2.75. It’s quite sustainable, as his xFIP was at 3.26, which is still good.
Because of his limited experience and background, he could be an elite arm, but he could also completely flame out. So far, he’s very polished for his age and is showing signs of being elite. He’ll look to face higher-level bats this year, assuming a move to the FCL, or if he has a great season, potentially a move to full-season ball. Overall, he has the stuff, the polish, and the frame to be a bona fide ace, but only time will tell.