Agent Silvio Pagliari has warned Atalanta against selling Papu Gomez in January.
The Argentine's future is in doubt after a furious bust-up with coach Gian Piero Gasperini last week.
Speaking with TMW, Pagliari said: "The only thing to think about is how much it will take to get Gomez. The Percassi family will not give him away. I know the mentality of Atalanta and their family, although there may be disagreements and so on, he has a price.
"I think back to the offers he had in the summer.
"Right now he is one of the few to really make a difference, in Bergamo they know it very well and I wouldn't be surprised if he was still there at the end of the next transfer market. A great club can succeed in repairing the pieces."
"Papu makes you win games and if he goes to Milan he'd do it for them. I don't think people so experienced make certain mistakes."