AC Milan chief Leonardo says Ivan Gazidis isn't arriving with a magic wand.
The departing Arsenal chief exec is set to join the new-look Milan management team with big expectations.
But Leonardo says: "We need to take responsibility, the whole club has to do it, clubs are there to win championships, we are building a team, it's normal that it is gradual and, I'm honest, I think the club should have a winning mentality too.
"We (the board) make an important contribution to the team around us to achieve results, we are under construction but aware that we must do something immediately."