Gary Neville has labelled Paul Pogba's agent Mino Raiola a "disgrace", and urged Manchester United not to work with him in the future.
Pogba, the World Cup-winning midfielder, finished last season as top scorer for United with 13 goals, but was linked with potential moves to either Juventus or Real Madrid in the summer.
"[Pogba] wants to leave. He has made it clear," Neville told Norwegian TV at the weekend.
"His agent is a disgrace and has been a disgrace all over Europe - not just for Manchester United. They must stop working with him. He doesn't have the values you want in your club.
"My opinion is that Manchester United need not negotiate with him. He will try to fix a transfer for his player, and will try to take part of the transfer sum himself. That's how he operates."
Neville feels the midfielder's attributes on the pitch are being negatively affected by his agent, who said in an interview back in July he was in the process of facilitating a move for Pogba away from Old Trafford at the behest of his client.
"For Manchester United, it's devastating. He is one of the best and most famous players in the world, but every week there are new issues," Neville added.
"There is always controversy. It's probably not his own fault, but the fact is that it is devastating for a club.
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"That's why Sir Alex Ferguson was at times clinical when he got rid of players. They were devastating.
"In a football club, everyone has to go in the same direction."
United have struggled at times this season, picking up eight points from five games in the Premier League so far.