Tsotsobe and Parnell to debut

South Africa will rest Dale Steyn and Makhaya Ntini for the final ODI of the series in Perth despite the fact that a victory would hand them the No. 1 one-day ranking ahead of Australia. With the series already won, the visitors will call on their two left-arm fast bowlers Lonwabo Tsotsobe and Wayne Parnell to make their one-day international debuts.

The batsman Vaughn van Jaarsveld is also likely to play his first game since debuting in Melbourne, provided he proves his fitness as he is battling an ankle problem. South Africa's bowling coach Vinnie Barnes said Steyn and Ntini would have played Friday's game had the series been alive but now they had an opportunity to take a well-earned break.

"It's just part of our rotation policy," Barnes told AAP. "We are looking long-term. We have to rest players, we are committed to that. We are not going to go into Friday's game thinking about losing or taking it as an ordinary game

"There's a huge commitment from everybody. We've got a couple of young players coming in who want to make an impact and secure their future so Friday night's game is as important as the game we've just played."

Parnell, 19, and Tsotsobe, who each played one of the Twenty20 internationals on this tour, will be especially keen to impress ahead of the return series in South Africa starting next month. Tsotsobe, 24, has had little to do but bowl in the nets for the past month and a half, having been part of the squad since the beginning of the Test series.

Ntini has taken Tsotsobe under his wing during the trip and he said he would be thrilled to see Tsotsobe make his debut at the WACA, where Ntini himself made his first ODI appearance 11 years ago. "I don't know which of the two of us is more excited," Ntini said.

"I have told 'Lopsy' [Tsotsobe] that this is the place where it all started for me. I still remember having Craig McMillan caught by Jonty Rhodes at point and then I got Stephen Fleming as well. I can't remember who my third wicket was. This is where he must make his mark. He must put down a big box and put all his eggs into it."

The youthful South Africa side will provide an extra confidence boost to Australia, who have regained Michael Clarke and Nathan Bracken for Friday's game. The Australians just managed to avoid losing their No. 1 Test ranking by taking the dead rubber in Sydney and Barnes said claiming the top ODI spot was not as important to South Africa as keeping Australia down.

"There's a bigger picture," Barnes said. "We don't want to give the Australians any breathing space. We've got them down 3-1 at the moment and we want to make sure that's 4-1. We want to give them absolutely nothing to bring to South Africa."