Gattoni spent his early years at local team Club Chacabuco, before signing for San Lorenzo at the age of seven.[3][4] He made his breakthrough into first-team football in October 2020, appearing for his senior debut in a goalless draw away to Argentinos Juniors in the Copa de la Liga Profesional on 31 October.[1][5] He had been an unused substitute once in each of the preceding two years; for a 2018 Copa Sudamericana loss to Deportes Temuco and for a 2019 Primera División win over Godoy Cruz, with a debut being further delayed due to serious cruciate injuries suffered in both knees in 2017 and 2018.[1][3][6][7]
Gattoni scored his first senior goal on 14 November 2020 against Aldosivi.[1]
On 3 July 2024, Gattoni joined River Plate on loan with the option to buy.[9]
International career
Gattoni was called up to train with the Argentine senior squad during a tour of Asia/Oceania in June 2017.[3] Two years later, he represented his nation at the 2018 COTIF Tournament; which they won.[10][11]