Roberto Fabián Ayala (locally [roˈβeɾto faˈβjan aˈʒala]; born 14 April 1973), nicknamed El Ratón ("The Mouse"), is an Argentine former footballer who played as a centre back for the Argentina national football team, as well as Valencia and Real Zaragoza in Spain, Milan and Napoli in Italy, and Ferro Carril, River Plate and Racing Club in his native Argentina.