The Florida Complex League Twins placed Castillo on the 60-day injured list July 2 with an elbow injury, Ian Cundall of Baseball America reports.
The 18-year-old middle infielder only played in five games in the FCL before suffering what appears to be a season-ending elbow injury. Castillo slashed .283/.395/.428 with two home runs and 12 steals in 39 games in the Dominican Summer League in 2025.