Rockies Top Relief Prospect Welinton Herrera Nears MLB Debut

Welinton Herrera, the Colorado Rockies' #1 relief prospect, is expected to make his MLB debut in 2026. The 21-year-old left-hander was added to the 40-man roster this offseason, showcasing a plus-plus mid-90s fastball (97-100 MPH). In 2025, he dominated High-A with a 0.49 ERA and 10 saves, then posted a 3.50 ERA with 7 saves in Double-A. Herrera, who represented the Rockies in the Futures Game and AFL, relies heavily on his fastball. He'll likely start 2026 in the upper minors.