Chelsea sign 19-year-old Mamadou Sarr from Strasbourg on long-term contract | OneFootball

Chelsea have completed the signing of Mamadou Sarr from RC Strasbourg, with the 19-year-old defender penning a contract until 2033.

The highly-rated centre-back becomes the Blues’ third signing of the summer, following the arrivals of Dario Essugo and Liam Delap.

Sarr joins after an impressive breakthrough season in Ligue 1, where he made 28 appearances and helped Strasbourg secure a seventh-place finish and UEFA Conference League qualification.

His move to Stamford Bridge was agreed during the January transfer window in a deal worth £12 million, but the transfer has only now been finalised.

Chelsea confirmed the acquisition in a statement today, hailing Sarr’s development and international experience at youth level with France.

The defender has featured for France at Under-17, Under-18, Under-19 and Under-20 level, with his progress drawing attention across Europe.

“Mamadou was a regular for Strasbourg during the 2024/25 campaign and played a key role in securing European football for the French club,” Chelsea wrote.

Sarr first emerged through the ranks at RC Lens before stints with Lyon and a loan spell in Belgium at RWD Molenbeek. He moved to Strasbourg last August and quickly earned a starting role.

His performances have drawn widespread praise, including from Strasbourg boss Liam Rosenior, who described the teenager as a player with the potential to become world-class.

“I could talk about him for hours,” Rosenior said. “His nickname is Mamadou Rosenior, he’s my son. It’s scary to show such performances at 19 with such calm in the face of such strong teams.”

“He just has to stay humble and calm and he will be a top player for sure. His temperament, athleticism and ability on the ball — he’s got everything.”

There are currently no indications that Sarr will be loaned out, and he is expected to feature in Chelsea’s upcoming Club World Cup campaign under new head coach Enzo Maresca.

The eight-year contract reflects Chelsea’s continued strategy of securing young talent on long-term deals as they reshape their squad for the future.

Sarr’s arrival adds further depth to a Chelsea defence in transition, with the club placing renewed emphasis on youth and potential heading into the new season.

“Welcome to Chelsea, Mamadou!” the club said, sealing the announcement.