Andre Villas-Boas' war of words with Alan Hansen has continued following the BBC pundit's latest swipe at Chelsea's defence.

Hansen's criticism of the Blues reached a new level last week during his analysis of their 2-1 Barclays Premier League win at Wolves.

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."

Luiz is expected to start against Sunderland, when Chelsea will have another chance to cut the 11-point gap to leaders Manchester City, who have lost three of their last four games in all competitions.

Villas-Boas said: "I don't feel the margin is unobtainable now.

"It's good that Tottenham are in the running now, because they can make it messier.

"What other teams see, though, is our inconsistency and that's been our cancer this season."

Martin O'Neill insists Sunderland will still be engaged in a fight for survival even if they beat Chelsea.

The Black Cats stunned the Blues last season when they returned from Stamford Bridge with a 3-0 victory.

This time around, they head for the capital on the back of a promising revival since O'Neill replaced Steve Bruce as manager in December, and having taken 13 points from a possible 18 and secured their place in the FA Cup fourth round.

That run has eased the Wearsiders into the top half of the table, although the Northern Irishman is adamant that he will continue to look over his shoulder.

He said: "Of course I am concerned, yes. If this was the final league table of the season, that becomes a different issue, but it is not.

"We could lose tomorrow and we could drop six places in the league, so it's still very, very tight.

"What we have been able to do, we have been able to haul ourselves into a pack of teams that I am quite convinced wouldn't be looking in any other direction than over their shoulder.

"Chelsea will be a difficult game for us, exceptionally difficult. But we are going in with confidence and we will see.

"If we win the game, it's three extra points for us and if we do that there, that would be fantastic for us, and that's the way I would look at it.

"Similarly, if we are beaten in the game, I'm hoping that it wouldn't dent confidence so badly that we would fall apart."

O'Neill's stance on the club's position has not wavered since he walked into the Stadium of Light, although asked if he is a man who generally views the glass as half-full or half-empty, he said with a smile: "It depends. It depends if it's half-full."

While Sunderland's recent form has edged them out of trouble, Chelsea have rather fallen off the pace in the race for the league title to leave manager Andre Villas-Boas and his players under pressure.

However, O'Neill is not being fooled by talk of their demise.

He said: "To start suggesting that these players are over the hill and not capable of contesting big Premier League games is just utter nonsense.

"They are still in the Champions League and they are sitting fourth in the league.

"They might be disappointed themselves that they have dropped more points at this stage than perhaps they thought they might do, but they are still a very fine side."

O'Neill could be boosted by the return of striker Nicklas Bendtner from a knee injury, while fellow frontman Fraizer Campbell was among the travelling party which left this afternoon for the first time since suffering a second serious knee injury in August 2010.

The manager said: "It is nice, but he has been out a fairly lengthy time, so we don't expect miracles at this moment. Just to get him fit and stay fit would be good news for us, and anything he does after that would be wonderful."

Midfielder Craig Gardner will also be at O'Neill's disposal with his manager desperate to hang on to him amid speculation that homesickness could force him back to the midlands.

He said: "Obviously, we would like him to stay, but we will see what develops and at this minute, nothing has developed."

Little has developed either on the incoming front with O'Neill adamant he is yet to sit down and discuss targets, although he intends to do that within the next few days.

He said: "I genuinely haven't had that much time to think about it. Of course, it crosses your mind, but to sit down and start going through things, I haven't had the chance to do that.

"I will do, obviously, next week."