If Franklin Primera had the best stateside debut of any Red Sox position-playing prospect this season, then Sadbiel Delzine had the best stateside debut of any of the organization’s pitching prospects.
Delzine originally signed with the Red Sox for $500,000 last January, receiving the largest signing bonus of any pitcher in the club’s 2025 international free agent class. Unlike his fellow countryman Primera, the Venezuelan native had plenty of eyes on him when he made his professional debut.
Due to a mild flexor strain, however, Delzine was limited to just 9 1/3 innings in the Dominican Summer League as a 17-year-old last season. The young right-hander showed flashes in that small sample, striking out nine and walking only one before being shut down, with the Red Sox wanting him to focus more on strengthening his shoulder and arm.
After using the offseason to add strength to his already sizable frame, Delzine — who turned 18 in January — arrived stateside in 2026 and came out of the gate firing in the rookie-level Florida Complex League. In 11 outings (seven starts) for the FCL Red Sox, he posted a 2.72 ERA with 43 strikeouts to 18 walks over 39 2/3 innings, limiting opponents to a .170 batting average.
That strong showing earned Delzine his first full-season assignment in a promotion to Low-A Salem in late July. From there, he closed out the year by posting a 2.52 ERA with 36 strikeouts to six walks in seven starts (25 innings) for the RidgeYaks. Opposing hitters in the Carolina League batted .219 against him.
Altogether, then, Delzine forged a 2.64 ERA with 79 strikeouts to 24 walks over 18 outings (14 starts) spanning 64 2/3 total innings between the FCL and Salem, with opponents slashing .190/.278/.249 in 267 plate appearances against him. He held right-handed hitters to a .221/.291/.311 line and left-handed hitters to a .158/.267/.184 line.
Among 36 Red Sox minor leaguers who, regardless of level, logged at least 60 innings this season, Delzine ranked second in ERA, third in batting average against, FIP (3.32), and WHIP (1.07), 10th in walks per nine (3.34), 11th in strikeout rate (29.6%) and xFIP (4.09), 12th in swinging-strike rate (13.5%), and 13th in strikeouts per nine (10.99) and walk rate (9%), according to FanGraphs.
Delzine, now standing at approximately 6-foot-5 and weighing between 235 and 255 pounds, is currently ranked by Baseball America as Boston’s No. 8 prospect, second among pitchers in the organization behind only Juan Valera. As noted in the publication’s scouting report, the burly hurler features a four-pitch mix. He has been up to 99.8 mph with his mid-to-upper-90s fastball while also mixing in a mid-80s changeup, a low-80s curveball, and a mid-80s slider.
“Outside of his raw stuff and command, Delzine has some deception in his operation,” Baseball America’s Geoff Pontes wrote last month. “He hides the ball well due to an accentuated pause in his layback. This motion tucks the ball behind his back hip, messing with batters’ timing.”
Like Primera, Delzine has the upside and ceiling to crack Baseball America’s top 100 list sooner rather than later. Barring a trade or other surprise move this winter, he is expected to return to Salem for the start of his age-19 campaign in 2027. That said, he should have the chance to work his way up to High-A Greenville before long.
(Picture of Sadbiel Delzine: Kelly O’Connor/sittingstill.smugmug.com)