Unai Nuñez grew up an Athletic Club fan in the Basque city of Portugalete and joined Lezama in 2007 when he was just 10 years old. After starring for CD Basconia and Bilbao Athletic the center-back was promoted to the first team over the summer of 2017. He made his debut on 20 August, 2017 and quickly earned a regular place in the lineup, featuring in 36 matches. Despite now being a well-known professional footballer, Nuñez is still a very reserved person. He regularly visits his family Portugalete where neighbors still remember him as the little kid who used to play football in the streets and now they watch him wear the Athletic shirt on television.
Unai Nuñez is under contract through 2023 and his deal contains a €30 million release clause.