Born in Cantaura, Anzoátegui, Venezuela, Amorebieta met Athletic Bilbao's eligibility standards, having been raised in the Basque Country, and through his parents, both of whom hailed from the region.
Born in Cantaura, Anzoátegui, Venezuela, Amorebieta joined Athletic Bilbao in 1996, aged 11. He met the club's eligibility standards having been raised in the Basque Country, and through his parents, both of whom hailed from the region.