Tiemoue Bakayoko moved to AC Milan on a one-year loan deal on Tuesday after just a season at Chelsea.
Milan announced the move in a statement on their official website and also confirmed there is an option in the deal for them to eventually sign the midfielder permanently.
Bakayoko will be unveiled as a Milan player on Friday.
Competition for places in the Chelsea midfield is fierce following the summer additions of Jorginho and Mateo Kovacic.
N'Golo Kante is a guaranteed starter when fit, and new Blues manager Maurizio Sarri started January signing Ross Barkley alongside the Frenchman and Jorginho as Chelsea beat Huddersfield Town 3-0 on Saturday.
Bakayoko, 23, endured a disappointing debut season with Chelsea last term, only sporadically producing the kind of form that persuaded the Blues to spend £40 million to get him from Monaco.
The Frenchman needs game time if he is to play his way back in to form, and it did not look as though he would be afforded many minutes at Stamford Bridge.
Per Matteo Bonetti of beIN Sports USA, there is also plenty of competition at the San Siro:
But Bakayoko has the quality to force his way into Gennaro Gattuso's Milan side, and he may well relish the opportunity to flourish in a new environment away from the pressures of the Premier League.
His Chelsea career is also far from over. Kovacic is only on a season-long loan at Chelsea, Barkley and Danny Drinkwater have yet to properly prove themselves in west London and Cesc Fabregas is in the latter stages of his career.
If Bakayoko can impress at Milan as they look to reestablish themselves as Serie A contenders, he could well return to Chelsea next summer with a chance to earn a first-team place.