The agreement has long been in place and on Tuesday Chelsea announced the signing of Christopher Nkunku.
The France forward moves for a fee of £52m from RB Leipzig to Stamford Bridge after the Premier League club triggered a release clause in Nkunku's contract.
While Chelsea have made numerous signings since the arrival of the ownership group led by Todd Boehly, Nkunku could be one of few that improves the squad significantly and brings Chelsea closer to Manchester City and the other Premier League powerhouses.
The 25-year-old is one of several high-quality attacking players coming out of France.