Boston Red Sox Breakout MLB Prospects For 2025

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Entering 2025, we’re projecting a number of Red Sox prospects to have the potential for a breakout season.

To qualify, a player must rank outside the organization’s Top 10 prospects entering the year. All scouting reports are from Baseball America’s 2025 Prospect handbook, which you can purchase here.

You can find Top 10 prospect rankings for all teams here and all breakout candidates here.

Red Sox Top Prospects For 2025

We rank the top players in Boston’s system entering the season, complete with new scouting reports, tools, grades & more.

Breakout Prospects

Juan Valera, RHP

Preseason Rank: 14
BA Grade/Risk: 50/Very High

Track Record: Valera signed for $45,000 just before turning 17 years old in 2023 and pitched out of the bullpen in an uneventful Dominican Summer League debut. However, after his first professional offseason, he made strength and arsenal gains that translated to more power and an improved ability to work in the strike zone. He was overpowering in the Florida Complex League and Low-A Carolina League in 2024, holding opponents hitless in eight of his 16 starts. His .125 opponent average was the lowest in the minors by a pitcher who logged at least 50 innings.

Scouting Report: The 18-year-old Valera showed a power pitcher’s build and stuff, with a fastball that sits at 95 mph with cut and tops out at 98. He also used a mid-80s slider and sweeper combination, using the slider in the zone to get ahead and the sweeper for swings and misses. Valera’s whiff rate against righties was roughly 60% in Salem. He’ll try to add more velocity to his slider to generate more separation in his mix. He primarily uses those three pitches but has shown a promising, splitter-ish changeup with fade that he needs to learn to keep in the zone. He could be a power bullpen arm, but given his uncommonly mature work habits and openness to instruction, he has a chance to start.

The Future: Valera will likely open 2025 as a starter in Salem but could get to High-A Greenville by the end of the year, with a chance to advance quickly for his age.

Scouting Grades: FB: 50. SL: 55. CH: 40. CTL: 50.


Payton Tolle, LHP

Preseason Rank: 15
BA Grade/Risk: 50/Very High

Track Record: Tolle spent two years as a two-way player at Wichita State before transferring as a junior to Texas Christian, where he focused mostly on pitching. The decision paid off with a 3.21 ERA and 37% strikeout rate. The Red Sox drafted him No. 50 overall in 2024, their highest selection of a pitcher since 2017, and signed him to a slightly over-slot $2 million bonus. He didn’t play after signing, spending his first pro summer training at the team’s development complex.

Scouting Report: The 6-foot-6, 250-pound Tolle is a mountain on the mound who uses his size to create a distinctive lefthanded look. He generates enormous extension, releasing the ball more than 7 feet in front of the rubber, while his low three-quarters arm slot seems like a cannon fired from the middle of a fortress wall. His low release height of 5.5 feet combined with excellent ride on his 91 mph four-seamer, which touched 96, created fits for college hitters. Tolle’s slider has average or better potential if he can throw it harder. His changeup was below-average but flashed potential. He also has a cutter and curveball. Though he’s physically maxed out, Tolle has remaining developmental runway as he focuses on pitching.

The Future: If everything clicks, Tolle could be a midrotation starter. Otherwise, he could be a swing-and-miss reliever. He should open 2025 in High-A Greenville’s rotation and could reach Double-A midway through the season. Tolle could emerge as a big league option by the middle of 2026.

Scouting Grades: FB: 55. SL: 55. CH: 40. CTL: 50.


Nelly Taylor, OF

Preseason Rank: 23
BA Grade/Risk: 45/High

Track Record: Taylor’s first love was the gridiron but that path was ruled out when, as a 5-year-old, he was diagnosed with a tumor in his kidney. He was a multi-sport athlete who ran track and played basketball before eventually focusing on baseball at Polk State JC in Florida, where he showed loud tools and made significant development strides as a sophomore to emerge as a day three pick. Taylor struggled early in his first pro season in 2024, little surprise given his adjustment to pro training environments, but finished with a .306/.389/.520 line in his last 27 games.

Scouting Report: Though no longer a football player, Taylor has the strength and explosive movements of one, resulting in pull-side juice to right field, albeit with a free-swinging approach and bat-to-ball limitations that create a power-over-hit profile. Still, he’s made rapid improvements in his training work and receives rave reviews for his work ethic, suggesting plenty of remaining growth potential. He has both excellent burst and impressive defensive instincts to create plus defensive potential in center field with additional value as a runner.

The Future: Taylor has big league-caliber defense. If he tightens his offensive approach, he has a chance to be a valuable fourth outfielder. His relative inexperience suggests no need to rush him through the lower levels. He’ll open 2025 at High-A Greenville.

Scouting Grades: HIT: 40. POW: 50. RUN: 60. FLD: 60. ARM: 50.

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