AC Milan CEO Adriano Galliani said the club will have to trim their playing personnel before any new players can be brought to the club.
Seven-time European champions Milan qualified for the last 16 of the Champions League last weeek and followed up with a 1-0 win over Juventus to hand the champions only their second defeat of the season on Sunday.
Now sitting ninth, albeit 14 points adrift of Juventus, things are looking rosier for the Rossoneri after they lost the spine of their squad over the summer and went on to begin the season in disastrous fashion.
Despite already losing big names like Zlatan Ibrahimovic and Thiago Silva, both to Paris Saint Germain, Galliani has not ruled out more departures.
"I suffered a lot from the sale of Ibrahimovic but the economic situation in this country is what it is," Galliani told www.acmilan.it.
"Ibra was a great player but he was luxury we could no longer afford."
Ibrahimovic's departure paved the way for Stephan El Shaarawy to come through to Milan's first team, and the 20-year-old has since scored 10 league goals to top Serie A's scoring charts.
"With Ibra in the side El Shaarawy may not have scored so many goals," added Galliani.
With the January transfer period on the horizon, Galliani said Milan, owned by former Italy Prime Minister Silvio Berlusconi, are in the selling market.
"We have 23-30 players. First we must sell then we can buy, when we have reduced the squad size," he added.
"We have some players who want to leave, not many, and others who we had already sold but who didn't accept the offers because they like it here at Milan.
"I have to thank president Berlusconi because for the last 26 years he has allowed Milan to eat and drink caviar and champagne.
"Now we may not have champagne every day but we do still drink it."