The 23-year-old will be returning to the Serie A where he previously enjoyed a five-year stint with Udinese. Portsmouth purchased the midfielder for $14 million before the start of last season and Muntari, who has made 42 appearances with the Ghana national team, quickly established himself in the first team, scoring seven goals over the course of the year. The move back to Italy is believed to be worth $25 million.
Portsmouth manager Harry Redknapp had previously been reluctant to sell the player, saying, "I don't want to sell him. He is one of my best players and is a terrific young talent."
Upon his arrival in Milan, Mourinho made it a priority to sign an attacking midfielder. Mourinho originally wanted Lampard, but it appears the England midfielder has decided to stay at the Premier League club for the time being.
Mourinho has also expressed an interest in Portugal winger Ricardo Quaresma. The 24-year-old Porto player has said he would like to move to a bigger club.