Villa manager Martin O’Neill has finally started to build up his squad of players – now comes the thankless task of keeping them all happy.

The manager leads the claret and blues to Sunderland for tonight’s Carling Cup fourth round tie facing a major headache. After already vowing to make changes – the question is how many? More to the point, how many can he get away with?

For the first time in his tenure, the Villa Park chief has a bench brimming with millions of pounds worth of internationals. As the Emile Heskey quit saga of a fortnight ago made clear, they will not be happy sitting on the bench forever.

Without the added demands of regular European expeditions, tonight’s game is both an obvious and rare opportunity for O’Neill to change things around.

But this competition now arguably represents Villa’s best chance of silverware this season, with Wembley just three rounds away.

A trip to the Stadium of Light would be a tough test for even his ‘strongest’ XI. Tinker too much and Villa could be out.

It’s a catch 22 situation and one Black Cats counterpart Steve Bruce and pretty much every Premier League boss in action over the next two nights faces.

O’Neill will try to find a balance – Emile Heskey, Brad Guzan, Luke Young and Fabian Delph seem the most likely starters.

But even that would still leave the likes of Craig Gardner, Nicky Shorey, Habib Beye and a certain Nigel Reo-Coker waiting in the wings. Not that the Villa boss wants any sympathy.

He said: “We have got strength and we will want to try to get through. I will have a wee think about it.

“Generally speaking here at the moment, if you are not playing in the side it is because someone else is playing better in your position.

“It is not really that new a problem for me. I had a similar problem at Celtic. We were able to extend to European scenes for quite some considerable time, so players did get playing time on the field.

“I do accept the fact it would be easier for a player to sit on Manchester United or Chelsea’s bench than it would ours.

“I have said before that when Manchester United change the team it’s called rotation, but when we do it it’s called leaving out or dropping. You only get that eventually with success. You look at Chelsea too.

“Some of the players there who would walk into other teams are prepared to battle it out because there is a chance they could be contesting a Champions League quarter-final, semi-final or even final.

“They have earned their right to have some players who sit out a few games. It’s not easily resolved. I think you are constantly aware of the players, particularly good players, in the squad who for one reason or another have not been able to get into the side and who may consider themselves a bit unlucky.

“The ones who are given that opportunity must go and grab it. There will be a number of players playing tonight who played on Saturday, also against Chelsea and Manchester City.

“It is up to them to maintain that consistency.”

That consistency was certainly missing in the first-half display at Wolves, a performance the manager deemed the worst of the campaign to date.

O’Neill said: “I don’t think you turn a blind eye to i. I think sometimes you can be a wee bit more forgiving, but no I don’t think I would do that.

“There is a difference between the two. You can play badly for a number of reasons during the course of 45 minutes or 90 minutes and it might not be reflective of what you’ve achieved for the team so far.

“You’ve got to keep people on their toes as much as you possibly can. If you’ve won 12 games on the trot and you lose the next two, then I think that somebody can say that that might be complacency.

“It isn’t in our case because we haven’t reached those heights yet.”

Villa, according to O’Neill, should fear no one having already beaten Chelsea and Liverpool this season.

But you won’t hear the claret and blue chief talking up his team’s silverware credentials.

He said: “We are a Premier League side, we feel we are capable on our day. I think we have shown this season that we are a match for anyone and we want to go to Sunderland to try to prove that.

“But we are miles away from winning a trophy. I wouldn’t start talking about winning cup competitions when we’ve got a Premier League side away from home, in a game which has to be decided on the night on their ground.”

O’Neill admits he is delighted to see his boyhood club’s fortunes on the up again.

He said: “I was a Sunderland fan as a kid and it is really pleasing to see them doing well. They’ve been away from Roker Park for a decade and now they are getting a good side together.

“The manager has done really well and they are improving and I am genuinely pleased to see them doing well, because they have got fantastic support.”

Villa have received a pre-match boost with the news Sunderland will be without red-hot striker Darren Bent.

The England forward, who has already scored eight goals this season, will be rested by the Black Cats boss as a precautionary measure after aggravating a knee strain in Saturday’s defeat to Birmingham.

Bruce said: “He has had a bad knock, it wobbled his knee a bit and gave him a fright. It was close to being serious but I don’t think it is fortunately. It’s not ligaments. He twisted his knee and rattled everything inside.”

The Black Cats, who are already without long-term injury victim Lee Cattermole, will call on Fraizer Campbell to take Bent’s place. Sunderland also have doubts over ex-Villa loanee Phil Bardsley, Bolo Zenden and John Mensah.