When he was 18, he won the Spanish League and Cup for players under 19 with the Athletic Bilbao junior team. Jupp Heynckes relied on him to play for the senior team in 1992, and Julen became the "Lezama's pearl".
He had the opportunity to sign up with Real Madrid, FC Barcelona or Italian clubs, but decided to stay in the Basque Country with his friends, his people and his loved club, wearing the number '8'.