Rooney has had a miserable World Cup so far and has not looked like breaking his nine-month international goal drought in England's dismal draws with the USA and Algeria.
Ferguson said he had spoken to his player and felt there were problems in the England camp.
Under pressure: Wayne Rooney has struggled to find his form in South Africa
He said: 'I get a feeling that the expectation is affecting England. Sometimes the expectation can be debilitating.
'I spoke to Wayne Rooney last week and said, "Relax and enjoy it". I sensed there was a tension in and around the camp.'
Just relax: Sir Alex Ferguson has told Rooney to enjoy the World Cup
Ferguson, whose Scotland side earned just one point in the 1986 World Cup, told US radio station Sirius XM this weekend that the Barclays Premier League may need to phase in a winter break for England to succeed at major tournaments.
'It's a real task to ask players to perform at the best level they can achieve after the season in England,' he said.
'Germany always take that month-long break in January.'
He has also watched France's struggles with interest, as former United defender Laurent Blanc is due to take over from coach Raymond Domenech after the World Cup.
The United boss observed: 'There seems to be a lot of disharmony in the camp.
'I think it was bad preparation for the players to know that Domenech was leaving.
'They should have brought Blanc along as an overseer or assistant. Maybe he would have had a calming influence.'
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