Injuries and form worry Australia

Australia's entire line-up today could not bat as long as South Africa's last three pairs survived on Sunday. For the 19,847 fans who turned up at the MCG on the fourth day it was a stark reminder that cricket's world order is changing. By the close of play South Africa were in sight of a historic series win and Ricky Ponting was left wondering what could be done to stem the bleeding.

Brett Lee has been all but ruled out of the Sydney Test with a foot injury but there are also questions over Matthew Hayden's form, Andrew Symonds' fitness, and the penetration of an attack that is still learning. Ponting has not given up on pulling out a surprise Melbourne victory but should the miracle not arrive, he knows he could be leading a new-look side into the third Test.

"If we win I don't think so," Ponting said of potential changes to the line-up. "If we lose they [selectors] might be thinking about it a little bit more. I'm really not sure exactly what's going through the selectors' minds. Changes seem to be made more when you're losing games, when you're winning games changes tend not to be made."

The man under the most pressure is Hayden, who again failed with 23, and Ponting said there was no indication of whether Hayden would be part of the batting order in Sydney. "We'll leave that up to the selectors to decide," he said. "We haven't spoken about any selections for next week just yet. That'll be done at the end of the game."

Hayden was one of several men who contributed to their own demise in the second innings when he drove Dale Steyn to a short cover who had been moved there two deliveries earlier. Ricky Ponting was again concerned about "a few loose shots" from his batsmen; Simon Katich flashed at a wide ball he should have left, Michael Clarke drove to cover and Ponting himself, although he batted superbly for 99, also picked out the man at short cover.

It was a trend that was greatly appreciated by Steyn, who collected 5 for 67. "I was gifted probably somebody like Michael Clarke's wicket today," Steyn said. "It was a really old ball, bad ball off the back foot, caught at cover. Really it's a gift. That ball could have easily gone for four as well. But it's the way they play, they like to score and sometimes that can be their biggest downfall."

A duck from Symonds was also a concern for Ponting, who had been criticised for not using Symonds at the bowling crease until on the third day. Symonds entered the match carrying a knee injury and Ponting said it would be reassessed after the game to determine whether he could play in Sydney.

"He's actually getting around the field okay at the moment," Ponting said. "I don't think his knee's gotten worse as the game has gone on but we'll have to obviously assess him at the end of this game and see how fit he is.

"Having someone very similar in Hauritz bowling for extended periods of time yesterday I went for the change-up of Michael Clarke and Hussey rather than going to another offspinner. As we saw with Andrew, he didn't look like getting a wicket for us yesterday."

A sore shoulder prevented Simon Katich bowling in South Africa's first innings but it won't be the part-timers who Ponting has to rely on for a come-from-behind victory in this match. South Africa need 153 with ten wickets in hand after surviving a six-over period late in the day. With Brett Lee's participation uncertain - he bowled three overs before stumps - Ponting needs something special from Peter Siddle and Mitchell Johnson.

"In their first innings we had them 7 for 190," Ponting said. "There's no reason why we can't create something very similar in the second innings if we execute everything as well as we can and we have a littler bit go our way as well. That's the only option we've got."