Francois Steyn has insisted the "calmness" Jonny Wilkinson brings to England poses a major World Cup final threat to South Africa.

The 20-year-old Natal Sharks centre is set to line up in the final on Saturday, but despite a relative lack of experience at Test level, he has seen enough of Wilkinson to know he could leave a significant mark on the game.

"We have not decided yet on a special plan [for Wilkinson]," Steyn said. "He is a key factor, but England have great forwards too.

"Jonny's drop goals are perfect, and if he gets the chance he will take it. He brings a calmness to their team."

Wilkinson was absent injured when South Africa thrashed England 36-0 in a pool game between the countries at Stade de France last month, but his return to the starting XV has coincided with a remarkable upturn in fortunes as England have reeled off successive wins against Samoa, Tonga, Australia and France.

Asked how much England have improved since that dismal Friday night in Paris, Steyn said: "One hundred levels. Maybe not that much, but they have got their stuff together pretty quickly.

"It's going to be a terrific game next weekend. I don't know who is going to win but I hope we can put on a good show.

"If England are on form on the day, it's going to be difficult to beat them. If we are on form, it's going to be a cracker.

"Our team has been together for four years now, and we know we cannot let this opportunity pass. For some of the players this will be their last World Cup. We have to come out firing."

Fourie du Preez, the South Africa scrum-half, also expects a vastly-improved England performance. "England don't kick as much as Argentina [South Africa's semi-final opponents] and they have a lot more attacking weapons in their arsenal, so our performance will definitely have to improve a lot," he said. "It is a new game, a final. It is a World Cup, and there have been a lot of surprises. Every game you watch, there is a new surprise.

"Jonny makes a huge difference in the team when he is directing the play very well. Just his presence gives the guys around him a lot of confidence, so we will have to be aware of that."