AC Milan chief Massimiliano Mirabelli has invited offers for goalkeeper Gigio Donnarumma.
Donnarumma was barracked by Milan fans during their 1-1 draw with Atalanta on Sunday.
“We must protect Donnarumma and we'll protect him to the end," the director of sport told Mediaset Premium.
“After that, as with all the other players, we'll see what happens. He is part of the club's heritage and we wouldn't let go of him easily, unless of course someone values him the way he must be valued.
“If a good enough offer arrived, any of our players could be sold. There are far richer clubs out there and we have to choose other paths.
“Let's not kid ourselves that we can return to being the Serie A of the past that attracted so many champions. We never will attract them. It'll be very difficult."