Australia's assistant coach, Justin Langer, has described Ricky Ponting as "an incredibly important part" of the Test side, despite his recent lack of runs.

122213 - Ponting incredibly important part of team - Langer

Langer warned against widespread changes to the team after the humiliation of being dismissed for 47 in Cape Town on Thursday, although he conceded it was not clear whether the team had hit bottom yet.

Australia fly to Johannesburg on Monday ahead of the second Test, which begins at the Wanderers on Thursday, and they will be without the injured Shaun Marsh. Usman Khawaja is expected to play in Marsh's absence, while David Warner will be flown in to join the squad but is unlikely to make the starting XI.

However, pressure is mounting on Ponting, who twice in the Newlands Test walked across his stumps and was lbw. Not only has he not made a Test hundred since January 2010, he has now played 12 innings since his last half-century. Mark Taylor survived a stretch of 21 innings without a fifty, but he was the captain and at 32, was four years younger than Ponting is now.

At Australia's optional training session on Saturday, after the Test finished inside three days, Ponting was one of only three batsmen who worked in the nets, along with Phillip Hughes and Shane Watson. Langer emphasised the "unbelievable" influence Ponting had in the team environment, despite his struggle for runs.

"We've got to be sensible about whether the guys you leave out or the changes you make are going to be replaced by someone better," Langer said. "Some might argue we've got nothing to lose and anything could be better. Well, maybe, but someone like Ricky Ponting has not only got 12,500 Test runs but his influence in the team is unbelievable. He's a really tough case. That's why he's working hard. At the moment, in my opinion it's really important Ricky Ponting is in this Australian cricket team."

While Ponting is expected to play at the Wanderers, it will be interesting to see how he is handled by John Inverarity's new selection panel. The new group will pick the squad for Australia's Test series against New Zealand, which starts on December 1, and Langer said Ponting knew he was under pressure to score runs soon.

"He's human," Langer said. "He'll hate me to say this, but I've seen McGrath, Steve Waugh, Matthew Hayden, Adam Gilchrist. They went through it. I love seeing that: they're human. I thought it was just me and the nuffies who weren't very good, who had self-doubts. He knows. He's a very grounded person. He knows how the system works better than anyone: you've got to score runs to stay in the team. He's determined to do that.

"No, he's not making as many runs as anyone would like at the moment. But he is an incredibly important part of this team. I say that without any hesitation."

All the same, it is difficult for Langer to grasp the current state of the side, having himself played in such a powerful era for Australian cricket. His challenge is to help Michael Clarke's developing outfit to find their way back up. Their series win in Sri Lanka pushed them up to fourth on the ICC Test rankings but the debacle in Cape Town was a massive blow.

"When I made my debut in '93, I came into a team of very senior players. Allan Border was the captain, Mark Taylor, the Waugh brothers - very senior team. From '89 to now we haven't been in a situation like this. Sport is cyclical, there's no doubt about that. Fortunately our cycle went a lot longer than usual. The reality is, we've seen over the last 12 months or a little bit longer, that our cycle has changed; I don't know if we've reached the bottom of it yet. I haven't seen it in my career."

Langer said it was hard to understand what had caused Australia's collapse on the second day at Newlands, but he described "game awareness" as a key area the squad had to work on. When Australia walked out in their second innings with a lead of 188, it appeared that they played too aggressively in the hope that extending their advantage by another 150 runs would be enough.

"In the past, really good teams would have thought we're going to bury these blokes and we're going to get 500 and we're going to do whatever it takes to absolutely bury them," Langer said. "Maybe we got a bit relaxed with it and thought we were going really well. We had a good tour of Sri Lanka and we were going well in this series. That's not how it works. With this group we need to keep getting much better at that."