The young goalkeeper joined Athletic Club in 2018-19 from Antiguoko. A confident shot stopper and strong in the air, Julen stands out most for his quick reflexes.

After playing for the Under 18s and Basconia, the goalkeeper quickly moved up to Bilbao Athletic, where he made a total of 40 appearances. Last season he got his first taste of senior football in LaLiga. Unai Simón's absence meant he started the campaign in goal, putting in some impressive performances.

The agile keeper split his time between the first team and the reserves in 2021-22, but he did become the first-choice stopper for the 2021-22 Copa, starting in all of the Lions' matches during their run to the semi-finals, which included victories over FC Barcelona and Real Madrid.

Julen's contract at Athletic runs until June 2025.