Mamadou Sarr from Strasbourg has officially joined Chelsea in a £12 million move. Having reached an agreement on an eight-year contract, the 19-year-old defender can now play right away in the FIFA Club World Cup in the United States.
Welcome to Chelsea, Mamadou Sarr! 🔵
— Chelsea FC (@ChelseaFC) June 9, 2025
This is the first senior transfer between Chelsea and Strasbourg, both of which are owned by Clearlake Capital and Todd Boehly under the BlueCo ownership model. With the intention of completing the transfer during the summer window, the agreement was concluded in January.
Sarr played in 28 Strasbourg games in all competitions during the 2024–25 season, helping the team finish seventh in Ligue 1 and earn a spot in the Conference League playoffs.
Sarr can play for Chelsea against LAFC on June 16 and Flamengo and ES Tunis on June 20 and 25, respectively, as Enzo Maresca will be leading his team in the Club World Cup in that tournament.
Chelsea sign 19-year-old Mamadou Sarr on long term
The 19-year-old, who signed an eight-year contract that would keep him with Chelsea until 2033, is the club’s second summer acquisition after forward Liam Delap, who joined for £30 million from Ipswich Town. Dario Essugo from Sporting Lisbon for £18 million and Estevao from Palmeiras for £29 million.
According to the club’s statement, “Chelsea is pleased to confirm the transfer of Mamadou Sarr from Ligue 1 side RC Strasbourg, with the defender signing a contract until 2033.”
After joining Strasbourg in August of last year, Sarr—a France Under-20 international—became a consistent starter in defense. He helped the team secure a spot in the UEFA Conference League play-offs for the following season with 28 games in all competitions.
A former midfielder with over 50 appearances for Senegal, his father, Pape Sarr, was a member of the team that won the Africa Cup of Nations and advanced to the quarterfinals of the 2002 World Cup.
