Luis De Leon Stats & Scouting Report

IP	11.0
ERA	4.09
WHIP	1.270
BB/9	6.6
SO/9	11.5

Full name Luis Mario De Leon
Born 04/14/2003 in Barahona, Dominican Republic
Profile Ht.: 6'3" / Wt.: 168 / Bats: L / Throws: L

Top Rankings

Organization Prospect Rankings

BA Grade/Risk: 60/High

Adjusted Grade: 45

Track Record: De Leon signed for just $30,000 as an 18-year-old from the Dominican Republic late in the 2021 signing period. From that unheralded start, he has grown to become one of the Orioles’ most promising and successful international finds in years. De Leon overpowered lower-level hitters when he came to the U.S. in 2023 but stumbled with command and execution in the second half of 2024 at High-A Aberdeen. De Leon missed time with an elbow issue early but rebounded there in 2025 and finished well, carrying a 1.80 ERA with 65 strikeouts in 45 innings over his last nine starts between Aberdeen and Double-A Chesapeake.

Scouting Report: De Leon’s raw stuff has always been among the best in the Orioles’ system. He boasts a four-seam fastball and two-seamer in the 95-98 mph range that yields a ton of weak, grounded contact. He throws a plus gyro slider in the mid 80s, an emerging mid-80s splitter and a plus changeup that’s a touch harder. De Leon’s secondaries have always impressed, but emphasizing fastball location to righthanded batters elevated his entire arsenal in the second half of 2025 as the rest of his stuff played up. De Leon’s command has always been inconsistent, but he has good zone rates with his fastball, suggesting it’s a trait that can continue to improve. Even in the zone, De Leon is hard to square up. He didn’t allow a home run in 87.1 innings in 2025, and he is regularly among the minor league leaders in groundball rate. In 2025, his 56.9% groundball rate ranked 12th among pitchers with at least 10 starts.

The Future: De Leon’s maturation and improved execution elevated his performance to a level that in many ways matches the frontline stuff he boasts. A midrotation starter’s role feels realistic now, and he could climb quickly toward that from his likely 2026 starting point at Double-A Chesapeake.

Scouting Grades: Fastball: 70 | Slider: 60 | Changeup: 60 | Split: 55 | Control: 45
BA Grade: 50/Extreme

Track Record: De Leon was a late-developing prospect in the Dominican Republic who signed for $30,000 at age 18 in December 2021 after Orioles scouts followed him past his age group’s signing year and noted his continued improvements. He made his U.S. debut in 2023 by dominating over six starts in the Florida Complex League before continuing his success at Low-A Delmarva. He struck out 11.2 batters per nine innings over the two levels.

Scouting Report: There’s plenty of projection in De Leon’s athletic 6-foot-3 frame, but his present-day stuff is hardly lacking. He averaged 95 mph on his fastball, giving it plus potential from the left side. He primarily attacks with his fastball and a high-80s changeup that can be an above-average pitch despite a small velocity difference from his fastball. That’s because of its significant horizontal fade and his ability to command the pitch. De Leon made progress with a hard slider in 2023 that gives him both another movement profile for hitters to consider and another potentially above-average pitch. De Leon’s ability to induce weak contact is an early strength, and opponents had a 69% groundball rate against him in 2023. Like many young power lefthanders, De Leon issued too many walks and will need to reduce free baserunners as he advances.

The Future: De Leon dominated light competition at the complex and during a late-season Low-A cameo, but he did so with the raw stuff and maturity that give indications he can be a midrotation starter at his peak. He’s likely to return to Delmarva to begin 2024, but could be pushed quickly should the Orioles like what they see.

Scouting Grades Fastball: 60 | Slider: 50 | Changeup: 50 | Control: 45