Jose Mourinho must not adopt a siege mentality at Manchester United if he is to be successful at Old Trafford, according to Ron Atkinson.
After winning his first four competitive games as United manager, Mourinho has seen his team lose three matches in eight days - including a 2-1 derby defeat to Manchester City.
The Portuguese was critical of referee Michael Oliver following United's 3-1 loss at Watford.
But Atkinson - who led United two FA Cup successes in 1983 and 1985 - does not believe an us-against-the-world approach will work for Mourinho.
"I have never been a huge fan of this siege mentality he brings to his clubs," Atkinson said.
"There's nothing wrong with being fiercely protective of your players, but that doesn't mean you have to antagonise everybody else.
"I don't think that approach would work at Manchester United because it can lead to the club becoming claustrophobic.
"It is a global brand and you cannot run it as your personal fiefdom. United is an expansive club, it's a club of the people. Telling everyone that 'It's us against the world' doesn't really wash, because United have lots of friends - they probably have more fans on the planet than anyone else.
"Jose has an engaging personality and it would be a shame if he got sidetracked by siege mentality and taking on the world."
Atkinson added: "I was surprised by the way United played in the derby.
"All credit to City, who look phenomenal, but I thought Jose would have set up his team to play higher up the pitch.
"It would have been an eye-opener for him to see the way City went about it, with David Silva and Kevin De Bruyne finding pockets of space.
"United were never outnumbered in midfield, but they were outmanoeuvred. You can't imagine that scenario if Roy Keane and Paul Scholes had been playing.
"For the first 10 minutes, they would have announced themselves, and tried to break up the little triangles City were forming, and I didn't see that in Jose's team in the derby."