 In La Liga, he played for Athletic Bilbao and Osasuna.Born in Barakaldo, Biscay, Expósito graduated from Lezama, Athletic Bilbao's renowned youth academy, and made his debut for the first team during the 1999–2000 campaign while also appearing for the reserve side.From 2003 to 2005, after a season-long loan with CD Numancia in the second division, he represented neighbours CA Osasuna also in La Liga.