The Italy international had been expected to leave the Allianz Riviera during the summer after he made it clear he wanted to pursue a new challenge.
Despite serious interest from Marseille, the enigmatic striker remains a Nice player and is now looking to earn his spot back in the team.
The 28-year-old returned to pre-season training two weeks late and was reportedly massively overweight, limiting him to just one Ligue 1 appearance so far this term.
Vieira, who had urged Nice to sell the striker during the summer, is now working on trying to integrate him back into the team and has named him in his squad for Saturday's clash against Montpellier.
The Frenchman appears ready to put his issues with Balotelli to one side for the good of the team and is eager to see him return to his best over the coming weeks.
"He doesn't have an issue, it's OK,' Vieira said. "I have always said that he needed time, he isn't yet at 100 per cent, but he trained all week, his attitude is good, he works well.
"Every day, I see a player who applies himself, who wants to find his level, to score and to play with his friends. When he is there physically, he is someone who is very important for us. He will travel to Montpellier, that's for sure."