Milan chief exec Giorgio Furlani rejected claims of selling Leao to Barcelona this week.
And Fonseca said today: "Our CEO spoke yesterday, I really liked what I heard. Rafa is fundamental in this team."
Meanwhile, the coach also said ahead of facing Parma: "In certain moments, when the ball is on the opposite side, he has to get closer to the goal. These players have to bring numbers, assists and goals. He has to understand this, he can improve his numbers. It's time to understand where to improve.
"I expect a very difficult match against Parma, against a particular team, which runs a lot. If we don't understand the type of match to play, it will be difficult for us to win, we won't just have to play, we will also have to fight. It is a type of match in which we will have to increase our defensive aggressiveness and we have worked on this."