Chairman of selectors Andrew Hilditch says senior players will retain their places as the Australian Test cricket side undergoes a major rebuilding phase.

Australia suffered its first home series defeat in 16 years with South Africa wrapping up the second Test in Melbourne yesterday.

In the first Test at the WACA ground in Perth, South Africa chased down an intimidating total of 414 on the last day despite making only 281 in the first innings.

South Africa now has a chance to clean sweep the series in Sydney and take the world's number one Test ranking.

Mr Hilditch says the selection panel will stick by the senior players in the team.

"Rebuilding has been going for some time, when I say senior players need to step up that's just the reality of international cricket," he said.

I mean we've got four or five really experienced players, great records and when they play, well it makes it easier for the rest of the team, for the younger players."

Skipper Ricky Ponting says his players must work hard to keep Australia among the world's top cricketing nations.

Ponting says his players must be more consistent over the five days of the match.

"What happened in this series is generally what Australia has done to teams in the past, when a big moments come up, grabbed it with both hands and turned a negative into a positive, then go on and be able to win games," he said.

The nine-wicket defeat at the MCG was the first time Ponting has lost consecutive Test matches as Australian captain.

He says Australia did not lift its game at pivotal points in both matches.
"We pretty much turned an unlosable game into into one we lost comfortably - that's really disappointing," he told ABC Grandstand.

"We've had out opportunities in the first two Tests and when the big moments have come up we haven't been good enough to put the nails in the coffin."

“Luck By Chance”

Meanwhile Victorian all-rounder Andrew McDonald says he was lucky to be called up for the third Test in Sydney.

McDonald got the nod after incumbent all-rounders Andrew Symonds and Shane Watson succumbed to injuries.

He will join a new-look Australian team in Sydney with Doug Bollinger and Ben Hilfenhaus also vying for a spot in the final XI.

McDonald says he did not expect the call-up.

"It's been forced changes so I think it's a lucky time for myself to be around the fringes of Australian cricket, their disappointment is my opportunity now," he said.

"I go to Sydney happy to be in the 12 and looking to contribute to Australian success down the track."

Australia's team physiotherapist says the heavy schedule of Test matches has contributed to the current injuries in the side.

Alex Kountouris says some players are over worked.

"Typically we have given them a rest during the one-day matches, I think we've just gone through a period where we have played a whole bunch of Test matches I think that's been difference to other situations," he said.

"Normally we would have some one-dayers in between and you rest here and there, but I think the importance of Test cricket to the team is one of the issues."