Benfica moved early for one of South America's most coveted teenagers, agreeing a deal with Vélez Sarsfield in December 2023 that was formalised on the player's eighteenth birthday, 31 January 2024, with a contract running until 2029.

Born in Ciudadela, in Greater Buenos Aires, Gianluca Prestianni came through the Vélez academy and made his professional debut in the Copa Libertadores in May 2022, aged only sixteen, quickly being singled out as one of the outstanding talents of his generation. At the Estádio da Luz the diminutive winger, direct and fearless in one-on-one situations, established himself as a regular option under successive coaches and helped the Eagles win the Supertaça Cândido de Oliveira in 2025. The 2025/26 season was his most complete in Lisbon, with a heavy presence in the side that completed the Primeira Liga campaign unbeaten.

An Argentina youth international at Under-17 and Under-20 level, he made his senior debut for the Albiceleste in November 2025.