Milan director Leonardo, however, cast doubt over the rumours prior to Thursday's 3-1 win over Olympiacos in the Europa League.
"Ibra has very close ties to Milan, everyone knows this," Leonardo told Sky Sport Italia.
"We cannot deny it was more than a brief thought going through our minds when we first arrived, as he is extraordinary and has very specific characteristics, but right now it's not possible."
Gennaro Gattuso, meanwhile, backed Patrick Cutrone to take up the mantle of Milan legend Filippo Inzaghi amid the links with Ibrahimovic.
Cutrone scored either side of Gonzalo Higuain's goal as Milan netted three times in the space of nine second-half minutes to come from behind and beat Olympiacos.
The youngster represented a rare bright spot in Milan's dismal campaign in 2017-18 and Gattuso believes Cutrone has the skill set to go on and match the career of San Siro great Inzaghi.
"I hope he can become the new Inzaghi," Gattuso told a news conference. "But he must keep working and keep his feet on the ground."