[2] Born in Junín, Buenos Aires, Muñoz started his career at his local village team Sarmiento in 1994, moving at the age of 20 to the Argentine giant club, Boca Juniors, after the 1997 FIFA World Youth Championship.

After two seasons in Argentina as substitute, in January 2005, Muñoz was signed by the Chilean side Huachipato for play the 2005 Torneo de Apertura.

[3] Muñoz was signed by defending Chilean Primera División champions Colo-Colo in July 2007 for an undisclosed fee, with the mission of replace to his countrymen Sebastián Cejas in the goal, who left the club for high costs.

With the Argentina Under-20 team, Muñoz won the 1997 FIFA World Youth Championship in Malaysia, being teammate of players like Juan Román Riquelme, Esteban Cambiasso, Luciano Galletti, Diego Placente, among others.

[4] He was substitute of Leo Franco during the tournament and played in the second round against England under-20 team, in a game that finished in a 2–1 win of his country.