Tottenham boss Andre Villas-Boas says it's difficult to predict how Manchester United will cope without Sir Alex Ferguson.

David Moyes will need to hit the ground running at Old Trafford if Manchester United are to retain the fear factor established during Ferguson's reign.

Villas-Boas said: "The fear that came from playing Alex Ferguson's sides made everything harder and that may still continue if adaptation is fast.

"That is something that I am curious to see."