HE won last season's Carling Cup with Birmingham City, but Sunderland midfielder Seb Larsson claims an FA Cup success with his current employers would mean an awful lot more.

Larsson was part of the Birmingham side that beat Arsenal at Wembley last February, only to suffer relegation to the Championship three months later.

He subsequently moved to Sunderland, and finds himself back up against the Gunners this evening in an FA Cup fifth-round tie at the Stadium of Light. Win it, and the Black Cats will be one game away from a semi-final appearance at Wembley.

Larsson knows what it is like to win a big game at the home of English football, but even though he regards his Carling Cup winners' medal as one of his greatest achievements, he is in no doubt as to what an FA Cup triumph would mean.

"I won the Carling Cup, but history wise and tradition wise this is bigger and better," said the Sweden international. "The FA Cup has never lost its spark to me.

"It has always been a special competition. Whenever I have been involved, I have wanted to go as far as possible. The furthest I have been is the quarter finals with Birmingham, but I have never thought that it is not important.

"Back home, the FA Cup was always a big thing to watch, and when you get to this stage, it can take on a life of its own."

In order to progress to the last eight, Sunderland will have to improve on last week's performance in a 2-1 defeat at the hands of today's opponents.

Thierry Henry scored a last-minute winner after Aaron Ramsey had cancelled out James McClean's 70th-minute strike for the Black Cats.

The defeat was only Sunderland's second in the space of 12 matches, a run that means they will enter today's game in a confident mood despite last weekend's setback.

"Confidence is high here," said Larsson, who made 12 senior appearances for Arsenal after graduating through the London club's academy and scored in Sunderland's 2-1 defeat at the Emirates in October. "We know we are playing well at the moment and beating teams.

"Last week we lost, but we had decent spells in the game and even when they had the ball we never really felt threatened.

"Maybe we were a little bit tired in the last ten or 15 minutes, but we had a tough extra-time game in midweek (against Middlesbrough) and we couldn't get forward as we would have liked."

Nevertheless, the improvement made under O'Neill has been staggering, with a side that appeared devoid of confidence, organisation and invention under Steve Bruce transforming themselves into one of the most in-form teams in the Premier League.

O'Neill's impact has been both immediate and considerable, yet he has not made a single signing of his own and has been fielding more or less the same players as Bruce. So how has he engineered such a radical improvement?

"It is really hard to put a finger on it," said Larsson. "It is hard to say exactly one thing that has improved us. The biggest thing is that he came in and showed tremendous belief in us straight away.

"He is an intelligent man. It is the way he says things. He gets his messages across in a very clever way. He makes you think about what he says, he makes you listen.

"He has managed to get the best out of most of us. He might talk individually to us, to build a relationship, but mainly it is in a group.

"Sometimes, he may not be happy with certain things, and want to shout or scream. But he mixes things up. He still gets the message across and makes you, when you go home, think about it.

"He has got us all doing quite well right now and we always knew we were capable of doing well because, when you look at the squad, there are a lot of good players. Lately, we have really got it going."

As a result, O'Neill's side will justifiably fancy their chances against an Arsenal side who are bound to be smarting from Wednesday night's Champions League horror show against AC Milan.

"Being a top club as Arsenal are and have been for a long time, one thing they do is respond well to bad results," said Larsson. "Most of the time, they respond quickly as well.

"Obviously we have to make sure we are ready for that response. I don't know whether the Milan defeat is good or bad news, but to be honest I'm not bothered. How they do in Europe is not my main concern - we just have to try to perform well."