Alonso Martínez is a Costa Rican winger and forward from Puntarenas. He began with Puntarenas and Alajuelense, had loan spells with COFUTPA and Guadalupe, and moved to Belgium with Lommel in 2021. New York City FC signed him in 2023, and he produced a breakthrough MLS season in 2024 after being used more centrally, including a 10-minute hat-trick against San Jose Earthquakes. Martínez made his senior Costa Rica debut in the 2021 CONCACAF Nations League Finals and has since become a regular attacker.