The Boston Red Sox No. 22-ranked prospect, according to MLB Pipeline, Allan Castro will become a minor league free agent at 5 p.m. ET Monday, likely departing the organization unless the Red Sox add him to their 40-man roster.
Boston must clear two more 40-man spots, or three if they decide to add Castro, and has not announced whether the No. 22 prospect in its system will fill one, according to MassLive‘s Chris Cotillo.
Castro, a 23-year-old switch-hitting outfielder from Santo Domingo, Dominican Republic, signed as an international free agent on July 2, 2019, for a $100,000 bonus. He began his career as a middle infielder before moving to the outfield, and he has yet to reach the majors.
He started 2026 as a non-roster invitee to big league camp and logged heavy playing time while Boston’s regular outfielders were away at the World Baseball Classic, according to SoxProspects. The Red Sox assigned him to Triple-A Worcester when camp broke.
Allan Castro’s Scouting Report and Season Numbers
Castro hit .252/.325/.397 with 15 home runs, 77 RBIs and 20 steals in 119 games for Worcester, playing all three outfield spots. He finished with a surge, batting .300/.371/.650 over his final 70 plate appearances and hitting six home runs in the last seven games. Four of those drives were tracked at 441, 410, 394 and 391 feet.
Across roughly 2,288 plate appearances in the minors, he owns a .251/.346/.404 line with 50 home runs and 82 stolen bases. He batted .268 with seven homers and 15 steals at Double-A Portland in 2025.
The 6-foot-1 switch-hitter has filled out beyond his listed 170 pounds and has little physical projection left, according to SoxProspects. He loads quietly, with a toe tap from the left side and a leg lift from the right, and he makes consistent contact in the zone. Velocity and offspeed pitches trouble him, and his pitch recognition needs work, which limits his hit tool to fringe-average.
His raw power grades above average and plays best from the right side, with most of his damage coming to the pull side. His speed ranges from fringe-average to average, and his arm grades average. Routes and instincts remain works in progress, pointing him toward a corner spot as he matures. The SoxProspects.com report projects him as a potential fourth outfielder or emergency call-up with a ceiling of second-division regular.
Boston Red Sox Roster Crunch and Allan Castro’s Future
Seven players on the 60-day injured list must return to the 40-man roster: Triston Casas, Zack Kelly, Eduardo Rivera, Eli White, Justin Slaten, Johan Oviedo and Kutter Crawford. Trades sending Nate Eaton to the Athletics and Tsung-Che Cheng to Detroit cleared a couple of spaces.
Boston does not typically add players solely to block free agency, according to MassLive, but Castro’s late power surge, switch-hitting and ability to play all three outfield spots have placed him in the discussion. The outfield has also dealt with injuries, including to Roman Anthony.
Castro is “definitely a consideration” for the 40-man roster, a source told MassLive‘s Christopher Smith. The move “has been considered, sources say,” MassLive‘s Chris Cotillo.
The formal Rule 5 protection deadline is Nov. 17, and a Castro re-signed to a minor league deal would become eligible for that draft, though a possible lockout clouds whether it will actually be held.
No decision on Castro had been announced as of 2:45 p.m. ET, with less than three hours left before the deadline. If the clock expires without a move, Castro can sign elsewhere or return to Boston on a minor league deal.
Red Sox Must Make Decision on Top-25 Prospect Today as Deadline Arrives