Manchester United boss Sir Alex Ferguson believes the reaction of the club's fans could force defender Rio Ferdinand out of Old Trafford.
The England star, jeered in United's last two pre-season games, has riled fans by stalling on a new contract.
"I'm not entitely happy with the reaction of the fans," Ferguson told MUTV on Wednesday.
"Players who go on the field and hear their own fans booing them is not encouraging at all."
Meanwhile, Manchester United's chief executive David Gill believes the club will soon reach agreement with the defender over a new deal.
The 26-year-old has rejected a reported £100,000-a-week offer but Gill told the club's website: "I am sure we will sit down and work something out.
"I understand the fans want to know what is going on.
"But Rio has said he wants to stay, Alex (Ferguson) wants him to stay and so do the owners and the board."
The England defender has two years of his current Old Trafford deal to run and it is thought that he wants £120,000 a week to sign an extension.
Some United fans are angry with Ferdinand over what they feel are greedy salary demands and booed the player in the match against Clyde and Peterborough.
However, Gill believes Ferdinand is right to take his time and consider his options.
He added: "It may be reflecting badly on Rio, but not with me it isn't.
"Yes, it is a lot of money by any stretch of the imagination but it is still a big commitment.
"You have to think about your worth. I respect him for that.
"It is a crucial time in his career and he needs to be happy with that."
Gill, though, also gave a veiled warning that Ferdinand is not in a strong position to engineer a transfer.
"There is no real pressure on it. It is not as if he can leave in a year's time," he insisted.
"He has two years to go on his present deal and we are not in a rush to sell in order to realise that capital."