Chelsea paid a transfer fee of approximately £52 million (about €60 million) to sign Christopher Nkunku from RB Leipzig in the summer of 2023. Later, in 2025, Chelsea sold Nkunku to AC Milan for a fee reported around €42 million (£36.2 million), including a sell-on clause. This transfer reflects a below initial purchase price sale, but aligns with Chelsea's trend of active player sales in recent transfer windows.