Tullio Tinti is convinced the Italy defender is set for a big season ahead with La Dea.
He told Sky Italia: "How much is he worth? Now unfortunately this bad injury happened to him, he is recovering with a smile. He's an out of class guy. I don't think Atalanta will be without a player like that, if they do so in the future I think they will ask for at least 50-60 million euros."
Tinti also spoke about Inter Milan defender Alessandro Bastoni, another of his clients: "I have seen him grow since he was 14 years old, he played as a left winger. He is a formidable player, he is a top player and in fact in recent years many clubs have knocked on Inter's door with the Nerazzurri club who, wanting to win, have never opened up to the possibility of his transfer.
"Who has come forward in the past years? Manchester City, in the last period Real Madrid but (president Florentino) Perez doesn't spend as much on defenders as he spends on attackers."