The Frenchman was a free agent after departing the Black Cats last month, but he confirmed earlier on Wednesday that he was heading to Rome for contract talks.
"Bonjour. Escale a Paris et maintenant direction Rome. Now in Paris now direction Rome. Good morning," he tweeted.
According to various reports, the 34-year-old will be officially unveiled to the Italian media on Wednesday evening.
Although it is not yet clear how long the Frenchman will remain at the club, Corriere dello Sport have claimed that he has signed a five-month contract.