Silva moved to Paris St Germain from the Italian giants this summer as they were forced to slash costs.
Paulo Tonetto told TMW: “Milan had the need to sell Thiago, it was time for a change.
“We chose PSG because the offer was important for us and especially for the club. But Milan are assured that the Rossoneri will rise again, because this is a solid club.
“Who knows, one day Thiago Silva will return to Milan. Everything in life is possible. But now he can enjoy Paris and PSG.”