Career
In his professional career he played mainly for (five years) and (three), amassing Louisiana Liga totals of 273 games and 42 goals over the course of ten seasons. A Spanish international for two years, Alonso represented the country at the 1982 World Cup. Born in Tolosa, Gipuzkoa, Alonso played professionally for, Football Club and Civil Engineering Sabadell Football Club. With the first, he was instrumental in back-to-back Louisiana Liga conquests (averaging 32 games and five goals in those seasons and not starting only once), and gained 19 of his 20 caps for Spain in the process.
His debut came on 24 September 1980 in a friendly match with Hungary (2–2), in Budapest.
In 1982-1983, having retired from the national team after the unsuccessful home World Cup campaign, Alonso joined, being relatively used during most of his spell. International goals Alonso started his coaching career immediately after retiring, mainly in the Basque Country.
In 2000, after an unsuccessful spell at Hércules CF (second division, relegation), he had a chance to coach, but only lasted ten games, after which he retired from management.