The 29-year-old, who is on £45k-per-week wages, is set to join Ligue 1 club Strasbourg over the next 24 hours, should he complete his medical.
The Ivory Coast international joined the Black Cats in 2016 and has been a divisive figure for the last two years. He made 24 appearances last season in the Championship for the Black Cats.
He made it clear to new manager Jack Ross that he wanted to leave the club, and it appears that Sunderland are finally being able to offload him.