The 22-year-old has been given one last chance at Marseille, following a recent bust-up with coach Didier Deschamps.
The French winger has been linked with clubs like Tottenham and Portsmouth.
“Ben Arfa can benefit from the injury to Niang,” Dassier told France Football.
“This is his last chance. I have plainly explained this notion.
“Clearly, he is not committed enough physically. He does not do enough for the team, does not sweat enough for the shirt.
“If that is what Didier thinks, I cannot contradict him.
“I regret this deeply because, as a player, he has what it takes to be a great. Now, if the market is interesting, we will study the offers, so if there is a good option, yes, but he won’t leave at any price.”
