Guglielmone began his career in Uruguay, making his debut for Nacional de Montevideo in 1999. After a year with them, he moved to Frontera Rivera, followed the next year by another move to Montevideo Wanderers. Guglielmone left Uruguay to join AC Ajaccio in the French Ligue 1 for the 2002–03 season, appearing 17 times and scoring just once, in the game against Sedan on 24 August 2002. However, after just a year in France, he returned to Uruguay, where he played for Danubio during the first half of 2004. He joined Pachuca for the 2004 Apertura, finishing the season with three goals in 11 games played, 6 starts.