Paulo Di Canio has made his fourth signing of the summer with the acquisition of midfielder El-Hadji Ba from French side Le Havre.
Mobido Diakite, Valentin Roberge and Cabral will also join the Black Cats on free transfers at the end of their current contracts.
Ba will similarly team up with Di Canio's side on a free transfer when his contract with Le Havre expires on July 1.
The 20-year-old midfielder has played three times for the French Under-20 side and will provide competition for places following the release of defenders Titus Bramble and Matthew Kilgallon.
