Roberto Fabián Ayala (locally: [roˈβ̞erto faˈβ̞jan aˈʒala]; born 14 April 1973), nicknamed el Ratón (in English: "the Mouse"), is a former Argentine footballer who played as a centre back for the Argentine National Football Team, as well as the Spanish giant Valencia and prominent Spanish side Zaragoza, the Italian giants Milan and Napoli, and the Argentine powerhouse River Plate.Regarded as one of the best central defenders of his generation, Ayala captained the Argentine national team in a record 63 matches. He played in three World Cups and made a total of 115 international appearances, with only Javier Zanetti getting more caps for Argentina. He inherited the nickname of Ratón from the Argentine 1974 World Cup player Rubén Ayala, although they are not related.