What happened: The 33-year-old center back arrives after spending the previous two seasons with Atletico Mineiro in Brazil's Serie A. His addition fills a senior international roster spot for Atlanta United.
Why it matters: The move brings veteran leadership to an Atlanta defense undergoing a broad roster overhaul under head coach Tata Martino. Sporting Director Chris Henderson highlighted the defender's top-flight European and South American experience as a stabilizing presence for the backline.
By the numbers: Alonso has logged 422 professional club appearances across six national first divisions, recording nine goals and 15 assists. He played 240 matches for Atletico Mineiro over three stints between 2020 and 2026, serving as captain and winning league and domestic cup titles in 2021. Internationally, he has earned 76 caps for Paraguay since 2013, including 12 CONMEBOL qualifying appearances and five matches during the national team's run to the Round of 16 at the 2026 World Cup.
What to watch: Alonso will be eligible to make his club debut once his International Transfer Certificate and P-1 visa clearance are processed.