Pierotti started his career in Colón's ranks; having signed in 2014.[3][4][5] He, aged eighteen, appeared for his professional debut on 12 April 2019 in the Copa de la Superliga against Tigre, replacing Marcelo Estigarribia after eighty-four minutes as the first round, first leg ended 0–0.[3][6]
On 13 January 2024, it was announced that Serie A club Lecce had reached an agreement with Colón for the permanent transfer of Pierotti, subject to the results of medical tests and international clearance.[7] The deal was made official three days later, as the player signed a contract until June 2027, with an option for another year.[8][9]
