Athletic Club midfielder Óscar de Marcos has put pen to paper on a three-year contract extension, which includes a €32 million release clause and will prolong his stay in Bilbao until 30 June 2016.

De Marcos joined the club from Deportivo Alavés in summer 2009 and has become a first-team regular this season thanks largely to his versatility. The 22-year-old played a key role as Athletic topped UEFA Europa League Group F to reach the round of 32 where they will face FC Lokomotiv Moskva.

Marcelo Bielsa's side travel to Russia for the first leg on 16 February before the return in Spain a week later.