The 27-year old Midfielder has struggled for game time at Fiorentina, he made 15 appearances since joining them from Sassuolo where he made 76 appearances in 4 years.
The former Inter Millan man joined Fiorentina last year January.
Cagliari becomes Duncan’s sixth club in the Italian Serie A since first joining Inter Millan nine years ago.
The Midfielder will wear Jersey number 32 at Cagliari.
Cagliari are lying 16th on the current Italian Serie A league table after 17 matches, only one separate them from the relegation zone.
By Francis Hema|3news.com|Ghana]]>