Career
A product of Athletic Bilbao youth academy, Díez kicked off his career with Bilbao Athletic. He played for various teams in Segunda División B before joining Civil Defense Ourense in Tercera División. In 2012, he signed for Portuguese Second Division club Chaves.
He scored his first goal for the club against Famalicão.
In his first season, Díez helped the club to secure promotion to Liga de Honra.