Chelsea have completed the signing of Strasbourg midfielder Valentin Barco on a seven-year deal.
The 21-year-old becomes Chelsea's sixth signing of the summer after the arrivals of Morgan Rogers, Danny Welbeck, Emmanuel Emegha, Maxence Lacroix and Marco Palestra.
The midfielder will join the remainder of Chelsea's pre-season tour, with the Blues set to face Italian side Juventus in Hong Kong on 5 August.
Chelsea did not disclose the fee.
Barco appeared once for Argentina at the 2026 World Cup, where they finished runners-up to Spain - and was slapped by Jude Bellingham after the semi-final victory over England.
A product of Boca Juniors' academy, Barco joined Brighton in 2024 for a fee of £7.9m.
But he spent just a year on the south coast, and joined Strasbourg the following summer after a successful loan spell.
He comes the second player this summer to join Chelsea from Strasbourg, with both clubs owned by Todd Boehly and Clearlake Capital.
It is the 13th deal between the two clubs since the start of last season.
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