Muntari, 30, spent the last three years at the San Siro with Milan following a move from rivals Inter, and made a total of 83 appearances in all competitions during his stay.
The Ghanian midfielder played just 16 Serie A games last season as the Rossoneri disappointingly finished 10th under the guidance of club legend Pippo Inzaghi, who has since been replaced by Sinisa Mihajlovic.
Competition from Premier League
Muntari has also been linked with a Premier League return with interest coming from Everton.
Muntari enjoyed a brief one-year spell with then Premier League side Portsmouth in the 2007-08 season where he made 29 appearances in all competitions for the Fratton Park outfit.
The one time champions league winner with Inter had previously been linked with a move to the MLS but it is believed interest has cooled.
Linked with Brazilian starlet
The 20-year old defensive midfielder has 9 Brazilian Serie A games to his name this season and is part of Brazil's U20 setup.
Reports from Sky Italia suggest the Stadio Artemio Franchi side are readying a €5.5 million offer for the player being likened to Paul Pogba.
More important matters to deal with
The club are currently attempting to deal with want away loanee Mohamed Salah and are reportedly even threatening legal action.
The Egyptian winger spent the second half of last season in Florence and part of the agreement in the loan allowed Fiorentina to extend for a further season with an option of a permanent move.
The player's agent Remy Abbas has branded the club's behaviour "pathetic" and admitted that his client "would like to play for a club with different moral and professional values."