Серро Портеньо
Díaz played at Club Tacuary School of Football for 1 year, before moving to Cerro Porteño. Díaz arrives at Cerro Porteño aged 10, at the club's school of football. He scored approximately 30 goals in the Cerro Porteño U15 team and was then moved to the reserves team. He was coached by Diego Gavilán in the U15 team. In 2013, he was referred to as the Sergio Aguero of Cerro Porteño as the reserves joined in on a practice session with the first-team.