Juárez started his career playing for Argentine first division side Club Atlético Lanús, where he was quickly recognized as a promising talent for the future.
In 1994, he was loaned to Uruguayan side Montevideo Wanderers where he had a fairly good season, and the next year he went back to Argentina to play for Lanus, and in 8 games he scored twice which got the attention of Mexican team Santos Laguna.
On his debut match against Espoli, Emelec won 4–0, Juarez scored twice and made the other two assists for his teammate and good friend Ariel Graziani, giving a preview of things to come.
Emelec rivals recognized Juárez as a major threat to their interests in every game and they used to change their defensive style to cope with his large physique.
This and Juarez great accuracy and vision to assist his teammates helped so that other forwards such as Ariel Graziani (twice), Jaime Ivan Kaviedes, Otelino Tenorio and Alejandro Kenig become Ecuadorian league top goal scorer.
However, in 2004 this was insufficient to convince him to stay and he left Emelec for free, to play for Spanish side Real Murcia, becoming the first Ecuadorian player to take advantage of Bossman's law.
Despite his good performances Emelec did not qualify for the final stages of the Ecuadorian league and Juárez went back to Argentina, expecting to be recalled for the next season.
New president Elias Wated and his group work, publicly disregarded Juárez as a signing for 2008, they said that he was too old, too fat, too slow, too problematic but overall too expensive for Emelec's budget.