First Test: Australia v South Africa
Venue: Perth Dates: 17-21 December Start time: 0230 GMT
Coverage: Scorecard and reports on BBC Sport website. Live on Sky Sports
Clark was pulled out of the squad after testing his elbow in the nets on Sunday
Pace bowler Stuart Clark will miss Australia's first Test against South Africa because of an elbow injury.
Clark has been struggling with the problem to his right elbow for a while and is due to see a doctor to see whether he needs surgery.
He has been replaced in the 12-man squad by Peter Siddle, who made his Test debut in the series loss in India.
The first Test in the three-match series between the top two sides in the world starts in Perth on Wednesday.
"It's extremely disappointing for Stuart Clark and the Australian team that his elbow injury has come at such an important stage of season," said chief selector Andrew Hilditch.
"However, it now presents another opportunity for Peter Siddle.
"He impressed in India on his Test debut and the National Selection Panel is sure that he is ready to take this chance."
Siddle looks set to compete with all-rounder Shane Watson for a place in the starting XI.
South Africa, meanwhile, have been boosted by the return to action of fast bowlers Dale Steyn and Morne Morkel following injuries.
They both took wickets in the tourists' drawn two-day warm-up match against the Western Australia XI.
AB de Villiers stood in behind the stumps as a precaution after Mark Boucher sprained his left ankle, but the veteran wicketkeeper is not regarded as a doubt for Wednesday's match.
"We should have a totally fit squad available for selection," said captain Graeme Smith.
"The boys are calm and relaxed but are also well focused and the confidence they have built up over the last 18 months will serve them all in good stead."
Australia squad: Matthew Hayden, Simon Katich, Ricky Ponting (captain), Michael Hussey, Michael Clarke, Andrew Symonds, Shane Watson, Brad Haddin, Brett Lee, Jason Krejza, Mitchell Johnson, Peter Siddle.
South Africa squad: Graeme Smith (captain), Ashwell Prince (vice-captain), Hashim Amla, Mark Boucher, AB de Villiers, JP Duminy, Paul Harris, Jacques Kallis, Neil McKenzie, Morne Morkel, Makhaya Ntini, Robin Peterson, Dale Steyn, Lonwabo Tsotsobe, Monde Zondeki.