Milan legend Marco Van Basten thinks Leonardo has betrayed the club by joining heated rivals Inter.
Leonardo accepted the offer to replace Rafa Benitez despite his 13-year history with Milan.
Speaking to Sky Italia, Van Basten said: "It's not right to pass from one family to another. Wouldn't it be a betrayal?
"In my case, yes. I was at Milan for many years. I found myself happy. In my opinion even Inter understand this way of thinking."
Asked for his reaction to Leonardo's appointment, he replied: "It's another thing entirely. He wasn't a Milan player for so many years.
"He left with problems. I have never had any with Milan."
Van Basten then gave an insight into his own future.
The 46-year-old Dutchman has been frequently linked with the Milan job in the past.
"Last year there were rumours, but no contact. I had the ankle problem. I had an operation in September. Now I am better.
"In the future you never know.
"There is quality at Milan, but they must improve in order to become a team that wins in Italy and in Europe.
"Ibrahimovic make the difference. He has done so many times this year.
"Zlatan played in a different way at Barcelona and the relationship with Pep Guardiola wasn't good.
"He is a sensitive kind of player. He needs the support of the Coach and the fans."