De León joined Nacional in 1977. With Nacional, he won two Uruguayan league titles, in 1977 and 1980, the Copa Libertadores in 1980. In 1981, he left Nacional to play for Gremio therefore missing the final game of the 1980 Intercontinental Cup which Nacional would subsequently win. With Gremio he won the Copa Libertadores and the Intercontinental Cup in 1983. After spells in Brazil and Spain he returned to Nacional in 1988, to win the Copa Libertadores and Intercontinental Cup in that year, and the Copa Interamericana and Recopa Sudamericana in 1989. At the end of the year, he left Nacional to play for River Plate of Argentina, where he won the 1989/1990 league title. He returned to Nacional in 1992 and won his third Uruguayan league title as a player. He retired in 1993.