Former Manchester United manager Ron Atkinson says Jose Mourinho's us-against-the-world approach won't work at Old Trafford.

Mourinho's United have lost three matches in eight days, including a home derby defeat to Manchester City and a shocking 3-1 loss at Watford on Sunday.

The Portuguese, who known to create outside enemies in hopes of creating a bunker mentality within his teams, was harshly critical of referee Michael Oliver after his side's loss at Vicarage Road. However Atkinson says the former Chelsea and Real Madrid boss must find another tactic with the Red Devils.

"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."

United were thoroughly outplayed in the first 45 minutes of their Manchester derby against City, ultimately falling 2-1 to their cross-town rival.

It was a result and performance that took the 1983 and 1985 FA Cup winner aback.

He 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."