Born in Campana, Buenos Aires Province, Martínez never represented any clubs during his youth setup (except from a year at Villa Dálmine at the age of 17).

[1] He played for hometown amateurs Club Las Acacias (which was presided by his mother) while working as a waste collector and bricklayer; at the former job, he was dismissed from his company after suffering a motorcycle accident.

[4] He scored 15 goals during his only season at the club, netting against Primera División side Belgrano and River Plate in the Copa Argentina.

On 18 June 2018, Martínez moved abroad and joined Paraguayan Primera División club Sol de América.

[9] The 16 goals he scored in 39 league matches allowed Instituto to retain their spot in the Primera División for their return to Argentina's top level after 17 seasons.