The former Liverpool captain claimed centre-half David Luiz "wouldn't know what a good position is if it was staring him in the face", adding of right-back Jose Bosingwa: "Bosingwa makes Luiz look like a world-beater at times. He is so bad it's embarrassing."

Villas-Boas has been unable to bite his tongue when it comes to Hansen's criticism since taking charge of Chelsea, launching a furious tirade against the 56-year-old last month.

His response to the Scot's latest jibes were more controlled but just as cutting.

"I really can't get myself involved with these people again," Villas-Boas said.

"Alan doesn't have the privilege that I have, to work with these players every day.

"If everybody had perfect games, first media pundits would have no jobs because there would be no one to criticise.

"You'd have to find jobs in professional football, which is a little bit harder."

Villas-Boas leapt to the defence of former Benfica star Luiz, who was initially a revelation when Chelsea made him the second-most expensive centre-back of all time last year but has been found wanting defensively this season.

"I think he's played fantastically since the start," Villas-Boas said.

"You have to agree that there are misconceptions created from the start, since the player's arrival.

"Sometimes a player has to carry that stamp for the rest of his life. Just maybe, you got that impression with David.

"I saw him in Portugal, and now I can work with him. He's going to be one of the greatest central defenders in the world. Because of his characteristics: technical ability, anticipation and speed.

"There is a nature in a Premier League game that you have to adapt to - it's culturally different to other countries.

"That might be a massive shock, to come from Portugal to England, but you've seen people succeed doing that."

Reports last night suggested Luiz may soon have a new defensive partner in the shape of Gary Cahill.

Villas-Boas is eager to bring the Bolton man in but talks over personal terms have been ongoing for almost a fortnight.

Speaking ahead of today's match against Sunderland Villas-Boas said he was hopeful of finalising the deal "this week" but it was reported that Cahill has travelled to London for a medical and is now ready to sign.

Meanwhile, Luiz himself has laughed off the criticism he has received, especially from former Manchester United defender Gary Neville.

Neville said earlier this season that Luiz played as if he was being controlled by a 10-year-old using a PlayStation.

Luiz told the Daily Telegraph: "I just laugh about it - because I am a very simple and laid-back guy.

"I also made sure that I replied to Gary Neville through Twitter and I told him that I loved him.

"He was an excellent player who played for many, many years for Man United.

"Any player needs to be prepared to face this sort of criticism, because if you are not, then don't play football, play something else, or just stay at home and play on the PlayStation!"

Luiz, who insisted he would not alter his all-action approach, also reciprocated Villas-Boas' unflinching backing.

"A lot of what is being said about Andre is undeserved," he said. He doesn't deserve this treatment of being talked about in this way at all.

"I know he is more than capable of turning things around. Later on, you are going to be talking loads about him and how wonderful he is, I'm sure of that."