Chelsea's £600 million ($723m) spending spree in 2022-23 was capped off with the £106.8m ($131m) signing of the 21-year-old midfielder, a British record fee.
Fernandez joined the Blues having spent less than half a year with Benfica, but with an impressive showing at the 2022 World Cup to his name, where he won the Young Player of the Tournament.
Chelsea's new No.5 impressed on his debut, and was one of the few high points in a drab 0-0 affair with local rivals Fulham.
Fernandez, then, has already shown promise, although many of his fellow countrymen haven't always enjoyed the same success during their time at Stamford Bridge.
With that in mind, GOAL takes a look at the Argentines to don the blue of Chelsea, as well as the one that got away...
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