Fofana is currently attending the La Madonnina Clinic to undergo medical examinations.
The France international is set to sign terms and be presented to the AC Milan support today at halftime against Torino.
Fofana will join for €25m and has penned a four-year contract.
Milan coach Paulo Fonseca said: "With the arrival of Fofana, the market is closed in terms of arrivals. We have to let players out, because now there are many of us and it is not easy to work with so many players.
"Now nothing is missing, because we haven't started yet When there is a change, it takes time to put it into practice. We are not a perfect team, in fact we are far from being one. But I don't want to talk about what we lack, I don't want to give points to our opponents by talking about it. I can say we are working on it."