Chelsea have completed the £12 million signing of 19-year-old French defender Mamadou Sarr from partner club Strasbourg.
Sarr has penned an eight-year deal and is eligible to play in this month’s Club World Cup in the US.
The transfer, agreed in January, marks the first player movement between Chelsea and Strasbourg, both owned by Todd Boehly and Clearlake Capital.
Sarr made 28 appearances for Strasbourg last season.
He joins Liam Delap, Estevao, and Dario Essugo as Chelsea’s summer recruits, as the Blues prepare to face LAFC, Flamengo, and ES Tunis in the Club World Cup.