Match facts
Friday, January 30
Start time 1.30pm (04.30 GMT)
The Big Picture
The similarities between this match and the Sydney Test are striking. Both turned into dead rubbers after South Africa claimed the series early and both provided opportunities for South Africa to claim the No. 1 ranking. Australia hope the parallels continue and they take a consolation win and hold onto top spot, as they did at the SCG. South Africa will rest some key players but neither team wants to give their opponent any extra confidence ahead of the return Test and one-day series in South Africa, which begins in a month.
South Africa's victory at Adelaide Oval on Australia Day gave them an unassailable 3-1 lead in the five-game contest. It was not the outcome that most observers expected from a one-day side that entered the series as the underdogs, led by the inexperienced captain Johan Botha. Now they can jump Australia on the ICC rankings with another triumph in Perth. That task will be harder without their strike bowlers Dale Steyn and Makhaya Ntini, while Australia have added strength to their line-up after what Ricky Ponting described as their worst performance of the summer on Monday.
ODI form guide
Australia - LLWLW
South Africa - WWLWW
Team news
Australia have regained Michael Clarke, who was resting due to a thumb injury, and Nathan Bracken after his minor calf problem. It adds significant strength to both the batting and bowling departments, with Cameron White and Shaun Tait making way. Ricky Ponting insisted that Tait's absence was not due to injury - he spent time off the field in the fourth ODI - but was simply a matter of managing his workload. It means they will need to rely on getting ten overs from the part-time spin of David Hussey and Michael Clarke.
Australia 1 Shaun Marsh, 2 David Warner, 3 Ricky Ponting (capt), 4 Michael Clarke, 5 Michael Hussey, 6 David Hussey, 7 Brad Haddin (wk), 8 James Hopes, 9 Mitchell Johnson, 10 Nathan Bracken, 11 Ben Hilfenhaus.
Steyn and Ntini are being rested at the tail-end of a tiring tour on which they have helped bowl South Africa to success in the Test and ODI formats. It means that the two left-arm fast men Wayne Parnell and Lonwabo Tsotsobe will make their one-day international debuts after appearing in one of the Twenty20 internationals. Jacques Kallis will also take a break, provided the batsman Vaughn van Jaarsveld proves his fitness after suffering a sprained ankle.
South Africa (likely) 1 Herschelle Gibbs, 2 Hashim Amla, 3 AB de Villiers (wk), 4 JP Duminy, 5 Neil McKenzie, 6 Vaughn van Jaarsveld, 7 Albie Morkel, 8 Morne Morkel, 9 Johan Botha (capt), 10 Wayne Parnell, 11 Lonwabo Tsotsobe.
Watch out for ...
Shaun Marsh entered the series under a form cloud but goes into the final game as the leading run scorer from either team with 213 at 53.25. His opening partner David Warner has captured the headlines but it is Marsh who has been more consistent in giving Australia a solid start. His technically correct, unfussy strokeplay has been welcome in an order where cross-bat slogs have been a little too frequent. It is also Marsh's first international appearance at his home ground at the WACA, where he has spent the past few seasons making his name at domestic level.
In the space of three weeks, Johan Botha has transformed from a captain who was struggling to control his Twenty20 side to a man who has led admirably in the 50-over format. Not only has he juggled his bowlers and placed his fields well, he has also led by example. Only Steyn and Ntini have taken more wickets in the series than Botha's seven at 21.42. He has been easily South Africa's most economical bowler and his variations in pace and flight have contributed to Australia's middle-order problems.
Pitch & conditions
Once famous for its pace and bounce, the WACA has lost its spice for international matches in recent years and a flatter surface was exploited by South Africa on the final day of the Test in December. While much of southern Australia is suffering through a major heatwave with temperatures around 42 degrees, Perth has escaped the extreme weather and a top of 30 is forecast for Friday.
Stats and trivia
The WACA is another venue where South Africa have had the better of Australia, winning two of the three ODIs between the teams.
Australia's recent record in Perth is not so bad though; only once in the past decade have they been beaten in a WACA one-day international.
No batsman has scored a century so far this series. The best was AB de Villiers' unbeaten 82 in Adelaide.
Quotes
"For us it's about playing the best cricket we possibly can and hope the opposition feels we're the best team in the world, but wherever we're ranked, in my opinion, is irrelevant."
Michael Clarke
"We are looking long-term. We have to rest players, we are committed to that."
Vinnie Barnes, South Africa's bowling coach