Mikel Arteta, the current Arsenal coach, was also part of the same youth team at Antiguoko KE. Roberto Montiel, the vice-president of Antiguoko KE and the coach of the three players during their youth, described Arteta as a small but technically gifted player with a strong competitive spirit. Iraola was a shy but talented right-winger, while Alonso showed exceptional vision and passing ability at a young age.
The partnership between Athletic Bilbao and Antiguoko KE, valid until 2030, includes a yearly payment and institutional support. This partnership is part of Athletic Bilbao's rule to only count Basque players in their team. The Basque region has produced several talented players, including Unai Emery, the current Aston Villa coach, and Zubimendi, who plays for Arsenal and the Spanish national team. The 2010 World Cup-winning Spanish national team had five Basque players: Unai Simón, Laporte, Mikel Merino, Nico Williams, and Oyarzabal.