Born in Amorebieta-Etxano, Cedrún started playing professionally with local giants Athletic Bilbao, making his first-team debut on 15 April 1951 in a 3–0 home win against Sevilla FC and quickly becoming first-choice.
[1] In the 1955–56 season, as the Basques won La Liga, he only conceded 31 goals while playing all 30 matches, and appeared in 402 official games during his 14-year spell.
[2] In 1964, having lost his place to another future club legend, José Ángel Iribar, Cedrún joined RCD Español also of the top division, again returning to starting duties.
[1] Mere months after retiring, Cedrún took a hand at coaching, starting in his region with lowly SCD Durango and Barakaldo CF.
Most of his career was spent in the lower leagues, his only top-flight experience coming in the 1976–77 campaign with RC Celta de Vigo, with the team ranking second-bottom.