The controversial striker did not feature in Nice's opening game of the season as they went down 1-0 to newly-promoted Reims and when asked after the game about his future, Vieira confirmed that Balotelli is looking to leave the club.
"The player wants to leave, so it's unlikely he'll remain here," Vieira told 'Canal+'.
"We want players whose desire it is to go forward with the club.
"It's a very complicated and difficult situation, so the club will try to do whatever is possible to help him leave."
Marseille are known to hold a very serious interest in the Italy international, thugh Napoli president Aurelio de Laurentiis has denied speculation that his side will make a move for the player.
The 28-year-old has scored an impressive 43 goals in 66 games for Nice since joining the club from Liverpool in 2016, earning himself and international recall as a result.
However, after plundering 26 goals last season, Balotelli is thought to feel that he has earned the opportunity to move to bigger club in a more reputable league.