Last week Roberto Mancini suggested rival managers do not stand up to Alex Ferguson and Villas Boas was non committal on the issue of whether visiting teams get deferential treatment by referees at Old Trafford.

"I certainly will have no problems expressing myself at Old Trafford," said the Spurs coach.

"I have no problem with that.

"It's an interesting question. It's a question that in this country is impossible to respond to.

"It would be good if we could respond but last year I received a very hard fine and I won't make the same mistake again."