Pakistan fast bowler Shoaib Akhtar has been omitted from the World XI squad to face Australia in the six-day Super Test starting at the Sydney Cricket Ground on Friday.
Shoaib was originally included in a 13-man squad but captain Graeme Smith told a news conference on Thursday the paceman had missed out on a place in the final 12.
South Africa's Smith said a decision on which of the remaining players would serve as 12th man would not be made until just before the start of play.
Australia captain Ricky Ponting said he also wanted to inspect the pitch on Friday morning before finalising the make-up of his side.
Both teams are expected to play two spinners on a Sydney pitch that traditionally favours slow bowling.
Shoaib is recognised as the world's fastest bowler but performed below his best in last week's one-day series in Melbourne, which the Australians won 3-0.
He conceded 110 runs without taking a wicket from just 17 overs in the first two matches of the series and did not play in the third game.
Australia: Ricky Ponting (captain), Justin Langer, Matthew Hayden, Michael Clarke, Simon Katich, Brad Hodge, Adam Gilchrist, Shane Watson, Shane Warne, Brett Lee, Glenn McGrath, Stuart MacGill.
World XI: Graeme Smith (South Africa, captain), Virender Sehwag (India), Rahul Dravid (India), Inzamam-ul-Haq (Pakistan), Brian Lara (West Indies), Jacques Kallis (South Africa), Andrew Flintoff (England), Mark Boucher (South Africa), Shaun Pollock (South Africa), Daniel Vettori (New Zealand), Steve Harmison (England), Muttiah Muralitharan (Sri Lanka).
Umpires: Simon Taufel (Australia), Rudi Koertzen (South Africa).