At international level, he represented Uruguay on 30 occasions between 1990 and 1997, scoring 11 goals, and also took part at the 1990 FIFA World Cup and the 1995 Copa América, winning the latter tournament.

[2] Fonseca, nicknamed el castor ("the beaver"), started his football career at Nacional, his local team in Uruguay, in 1988.

During his time with the Turin club, he won one Serie A title, a Champions League runner-up medal and the Supercoppa Italiana.

His only match was a pre-season encounter against archrivals Boca Juniors, and Fonseca helped his club to earn a win by scoring the final penalty in the shootout.

[13] He was a member of the team that took part at the 1990 FIFA World Cup, scoring in injury time in the final group game against South Korea, and was also in the squad that won the 1995 Copa América.

[3][4][7][15][16][17] Fonseca currently works as a football agent, and has represented several of his compatriots, including Martín Cáceres,[18] Fernando Muslera,[19] and Luis Suárez.