Scouting Report

Scouting grades: Hit: 40 | Power: 55 | Run: 60 | Arm: 70 | Field: 50 | Overall: 45

Born in the Dominican Republic, Rosario grew up in New Jersey before moving to South Carolina for his high school senior season in 2023. The younger brother of Padres infielder Eguy Rosario, he stood out with his physicality and raw tools on the showcase circuit, though he also was dogged by swing-and-miss issues and lasted until the Cubs took him in the sixth round. He finished fourth in the Single-A Carolina League in both homers (16) and strikeout rate (32 percent) in his first full pro season before Chicago traded him to the Guardians for Eli Morgan in November.

Rosario is a study in extremes as a right-handed hitter. On the positive side, he has more bat speed and strength and generates more raw power and higher exit velocities than most 20-year-olds. But he's also overly aggressive, tries to launch every pitch he sees to his pull side and struggles to recognize or deal with non-fastballs.

Rosario's big swing slows him down coming out of the batter's box, but he can flash well above-average speed once he gets going and he knows how to use it on the bases. His quickness gives him a chance to remain in center field if he can hone his defensive instincts. If not, his plus-plus arm strength is perfect for right field.

Scouting grades: Hit: 35 | Power: 55 | Run: 60 | Arm: 70 | Field: 55 | Overall: 40

The younger brother of Padres infielder Eguy Rosario, Alfonsin was born in the Dominican Republic and grew up in New Jersey before moving to South Carolina for his high school senior season. He impressed with his physicality on the showcase circuit, though he also came with significant swing-and-miss concerns. A sixth-round pick by the Cubs in 2023, he showcased some of the best all-around tools in their system before they traded him to the Guardians for Eli Morgan in November.

Already 6-foot-1 and 215 pounds, Rosario generates well-above-average raw power and high exit velocities with strength and bat speed from the right side of the plate. He can flash similar speed and plays more as a plus runner who looks to steal bases. He also offers double-plus arm strength and could develop into a solid center fielder, though some scouts think his instincts will land him in right field.

It all comes down to the bat with Rosario. He's an extremely aggressive hitter who looks to pull every pitch he sees and struggles to recognize and adapt to breaking balls and changeups. He struck out at a 35 percent clip in his first two months in Single-A this season and he'll need to prove he can make adjustments, especially as he advances to face higher quality pitching.

Awards

MID Post-Season All-Star

Year	Team
2025

MID Player of the Week

Week	Team
07/06/2025

Transactions

Team	Date	Transaction
	10/20/2025	OF Alfonsin Rosario assigned to Surprise Saguaros.
	10/15/2025	Estrellas Orientales activated OF Alfonsin Rosario.
	10/15/2025	OF Alfonsin Rosario assigned to Estrellas Orientales.
	08/05/2025	OF Alfonsin Rosario assigned to Akron RubberDucks from Lake County Captains.
	03/27/2025	OF Alfonsin Rosario assigned to Lake County Captains from Lynchburg Hillcats.
	03/06/2025	activated RF Alfonsin Rosario.
	11/20/2024	Cleveland Guardians traded RHP Eli Morgan to Chicago Cubs for RF Alfonsin Rosario.
	11/20/2024	OF Alfonsin Rosario roster status changed by Cleveland Guardians.
	11/20/2024	RF Alfonsin Rosario assigned to Lynchburg Hillcats.
	04/25/2024	OF Alfonsin Rosario assigned to Myrtle Beach Pelicans from ACL Cubs.
	03/16/2024	OF Alfonsin Rosario assigned to Chicago Cubs.
	08/02/2023	OF Alfonsin Rosario assigned to ACL Cubs.
	07/16/2023	Chicago Cubs signed OF Alfonsin Rosario.
	06/14/2023	OF Alfonsin Rosario assigned to College Workout.
	07/18/2022	High School Workout activated OF Alfonsin Rosario.
	07/18/2022	OF Alfonsin Rosario and assigned to High School Workout.