He and Argentina's Neri Cardozo are the only players to have won both the Concacaf Champions League and the Copa Libertadores, America's top two international tournaments.

[1] On 31 May 2015, aged just 16, he made his first team – and Primera División – debut, coming on as a late substitute for Martín Ligüera in a 2–0 away loss against Peñarol.

He scored his first professional goal on 25 March of that year, netting the winner in a 2–1 home defeat of El Tanque Sisley.

[4] On 29 July, he scored a hat-trick in a 5–0 away routing of Cerro,[5] and finished the campaign with 11 goals, playing a key part as his side narrowly avoided relegation.

On 5 January 2025, Peñarol reached an agreement to sign Fernández for a reported fee of US$7 million, a record for uruguayan football.