Diakite arrived at the Stadium of Light from Serie A side Lazio in the summer on a free transfer, but made only seven premier league appearances in a dismal six months on Wearside.
Diakite returned to Serie A in a loan deal to Fiorentina on Deadline Day, with an option to make the move permanent in the summer, and his agent Ulisse Savini admits he regrets bringing his client to England.
He told the Italian media: “Modibo has a great desire to get back to the Italian league with an important team.
“We are happy, he has five months to get his games and prove his worth, and show that he is a major player. He left Lazio and it’s not gone in the best way, that is true.
“Sometimes in life you make choices which, with the benefit of hindsight, you would not do.”
The French-born defender will be keen to impress in his second stint in Italy, having performed admirably for Lazio. At 26-years-old, Diakite may still have much to offer, should he perform well with Fiorentina.