The Mets non-tendered Castillo on Friday.
Just two weeks after claiming Castillo off waivers from Baltimore, the Mets will now send him into free agency. The 29-year-old southpaw posted a 3.94 ERA and 1.69 WHIP across 32 innings between four different teams in 2025. He'll now have an opportunity to pick where he begins the 2026 campaign, though he may have to settle for a minor-league deal.