Red Sox Weigh Adding Allan Castro to 40-Man
Boston must decide by Monday whether to protect No. 22 prospect Allan Castro or let him become a minor league free agent.
Updated on Nov. 2, 2026 in Baseball
The Boston Red Sox must decide whether to add outfielder Allan Castro to the 40-man roster before a 5 p.m. ET deadline Monday, or he becomes a minor league free agent. Castro, ranked No. 22 among Red Sox prospects by MLB Pipeline, has yet to reach the majors.
Why it matters
Adding Castro would require Boston to clear two more 40-man spots, or three if it adds him, while seven players on the 60-day injured list must return to the roster. The outfield has dealt with injuries, including to Roman Anthony, which has placed Castro in roster discussion.
Castro hit .252/.325/.397 with 15 home runs, 77 RBIs and 20 steals in 119 games for Triple-A Worcester in 2026, batting .300/.371/.650 over his final 70 plate appearances. Whether Boston adds him to the 40-man roster before the Monday deadline remains undecided.
The players
Allan Castro
A switch-hitting outfielder from Santo Domingo, Dominican Republic, who signed with the Red Sox as an international free agent in 2019 and has yet to reach the majors.
Boston Red Sox
The Major League Baseball club based in Boston, which must decide whether to add Castro to its 40-man roster before the Monday deadline.
The details
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 2026 as a non-roster invitee to big league camp before Boston assigned him to Triple-A Worcester when camp broke.
Timeline
Monday, 5 p.m. ET: Castro becomes a minor league free agent unless added to the 40-man roster.
Nov. 17: Formal Rule 5 protection deadline.
Season Trajectory
The decision reflects the annual Rule 5 protection deadline, which forces teams to add prospects to their 40-man rosters to shield them from the draft. Castro's late-season power surge and ability to play all three outfield spots place him among the candidates Boston must weigh against its injury-depleted outfield.
If Boston does not add Castro by Monday, he becomes a minor league free agent and could sign elsewhere. Adding him would also push another player off the 40-man roster, shaping which prospects are shielded from the Rule 5 draft.
The takeaway
Roster deadlines force teams to weigh unproven prospects against injured veterans, and Castro's late surge makes his inclusion a real decision rather than a formality. Readers following Boston's outfield should watch the Monday deadline closely.
What happens next
Boston must decide by Monday at 5 p.m. ET whether to add Castro to the 40-man roster, and the formal Rule 5 protection deadline falls on Nov. 17.
Further reading
For more on the team's roster moves, see Baseball coverage in Boston.
Source note: This article includes information reported by Heavy.
