Chelsea complete 4th signing of the June 2025 transfer window

Chelsea have completed their fourth player signing as the 2025 June transfer window intensifies ahead of the Club World Cup.

Chelsea have officially secured the signing of 19-year-old defender Mamadou Sarr from their sister club Strasbourg in a deal worth £12 million making him their fourth signing in the jUne 2025 transfer window ahead of the club world cup 2025.

The French youngster has committed to an eight-year contract and will be available for selection in the upcoming FIFA Club World Cup in the United States.

Chelsea will kick off their campaign against LAFC on 16 June, then face Brazil’s Flamengo on 20 June, before concluding the group stage with a match against Tunisian champions ES Tunis on 25 June.

Although the agreement for Sarr was reached back in January, both clubs waited until the summer transfer window to finalise the move. Sarr featured 28 times for Strasbourg across all competitions last season, helping the team finish seventh in Ligue 1 and secure a place in the UEFA Conference League play-offs.

This deal marks the first player transfer between Chelsea and Strasbourg since both clubs came under the BlueCo ownership group, led by Todd Boehly and Clearlake Capital.

Sarr becomes Chelsea’s fourth signing of the summer, joining Liam Delap (£30m from Ipswich Town), Estevão (£29m from Palmeiras), and Dário Essugo (£18m from Sporting Lisbon).