His €3 million per season contract offered by the Italian giants is in serious danger as it could be slashed €1.3 million.
This means the Ghanaian is likely to lose €1.7 million – insiders to the deal reported on Sunday.
Muntari suffered a serious injury while playing with friends in Accra last week during his summer break.
He suffered ligament damage while playing at the Bawaleshie Park in Accra and will be out of action for at least five months.
AC Milan CEO Adriano Galliani is furious over the injury and he is now considering almost halving his offer for the midfielder’s services.
The 27-year-old joined the club on loan from Inter during the January transfer window and impressed during the second half of the season which prompted the decision for him to be handed a permanent deal.
AC were ready to offer Muntari a two-year contract worth €3 million per season but the freakish injury has forced to make some unexpected but essential extra expenditure.
According to Corriere dello Sport the Rossoneri are considering lowering the offer to Muntari as they have been forced to sign Kevin Constant on loan from Genoa as a replacement.
The paper claims that angry Galliani’s contract offer on the table for Muntari will be €1.3 million less than the previously agreed figure.
Muntari made 13 appearances for the Rossoneri last season, scoring three goals.