DEFENDER Paul Williams believes that Saints can't be worried about the opposition's strengths if they are to beat Manchester United at St Mary's tomorrow.

Williams is expected to line-up alongside Michael Svensson for the visit of Sir Alex Ferguson's men with Claus Lundekvam again rated highly doubtful with bruised ribs.

And the 31-year-old centre half is ready for the test that United will bring and insisted: "Like any game we have got to try and be defensively sound and create chances for ourselves.

"We've got to try and impress ourselves on the game and not sit back and wait for something to happen.

"I think this game is one of toughest, but we showed against Arsenal we can beat the top teams and we need another display like that."

If he plays, Williams will find himself up against the awesome Ruud van Nistelrooy, who has scored 25 goals in all competitions this season.

There is still plenty of debate raging about who is the Premiership's best striker - Van Nistelrooy or Arsenal's Thierry Henry.

Williams says they have very different games but is looking forward to marking the Dutchman tomorrow.

"He's up there among the best strikers around," said Williams of Van Nistelrooy. "People compare him to Thierry Henry but they are two different strikers.

"Van Nistelrooy has lots of strength but not the same speed, but he does know how to finish.

"Arsenal and Manchester United have different ways of playing and Thierry Henry is capable of getting a goal by himself but they are both great strikers."

Lundekvam's injury has opened the door for Williams, to re-establish himself in the first team.

Having started the first seven games of the season, the big defender was forced out of the side through suspension - he was sent off in the 1-0 loss at West Brom - and, until the FA Cup tie with Millwall, had not started a game since the end of September. But he said: "It's obviously a bit tough not playing for so long but I think I have done OK.

"It's down to each individual to keep yourself fit but no matter what you do in training and reserve games there's nothing like playing the real games.

"It's been hard because every professional wants to play.

"I went out of the team through suspension and Michael did very well but now I've got my chance and hope to stay in there."