Wales believe they will need to score two or three tries to beat South Africa in their World Cup 2011 Pool D match at Wellington Regional Stadium on Sunday.

But to do that, they will need composure in attacking situations to beat a hard working and efficient South Africa defence, said attack coach Rob Howley.

"This game is all about scoring tries and from my perspective we're going to need to score two or three tries if we're going to win the game," Howley told the media.

"When we create opportunities and we get in behind lines we have to make them count because this South African side works tirelessly off the ball, particularly in defence.

"It would be a huge factor if we don't show composure. But we have shown composure in our last three games, so hopefully that will continue."

Howley said they would also need to defuse an expected aerial assault from the defending champions and to maintain discipline if they were to prevail.

"We have to make sure we don't give any silly penalties away because keeping discipline needs to be first and foremost.

"South Africa have a very good power game and it's important we dominate the sky. The aerial kicking game is so important when you play South Africa."

Three Wales players remain in doubt with calf injuries - prop Gethin Jenkins, loose forward Ryan Jones and flyhalf Stephen Jones - and Howley said no chances would be taken by rushing them back too early.

"If you look at the three boys who have done their calves, they need a little more time than anyone else and... at World Cup time they are invaluable on and off the field.

"And if they are slightly injured, they are still great to have in the squad."

Despite the injuries Howley said the squad was in good shape. All that remained was to convert their preparation into a winning performance.

"We are happy and comfortable where we are at with our physical hardness.

"With South Africa, our results over the last few years against them with three, four, five-point losses, hopefully we can get a little bit of luck and turn it into a win on Sunday."

RNS