Carter puts on a brave face as he recalls moment his world ended

All Blacks star discusses 'gut-wrenching' injury and gives backing to understudy Slade

Steve Hansen sighed. It was not the sigh of a man on the point of admitting defeat – far from it – but the New Zealand assistant coach was undeniably downcast. "How did we react when we heard the news about Dan? We're the ones setting the tone, so we had to be positive," he said. "You fake it until you can make it, don't you? We're well past the worst of it now, but let's not pretend this isn't a setback."

Hansen was talking about Daniel Carter, stellar outside-half and one of the All Black nation's two sporting superheroes, the other being his long-time colleague Richie McCaw, who also happens to be struggling for fitness. Not that McCaw is anywhere near as badly crocked. The captain missed last weekend's romp against Canada with a foot injury but is now, according to the coaching team, "looking like a million dollars and raring to go" in Sunday's quarter-final meeting with Argentina. Carter? He's going nowhere. Not in what is left of this competition, at least.

The world's best No 10 broke down with a groin injury during kicking practice on the eve of the Canada fixture. "I knew it was quite serious because of the pain, which was quite unusual," he said yesterday. "I've kicked thousands of balls since I was a youngster and never felt anything go 'pop' like that. It's gut-wrenching. I've never had any groin problems, adductor problems, hip problems: this has come out of the blue. I'm continually asking myself why it's happened now, but I haven't come up with any answers."

Irony of ironies, Carter had promised himself a shorter session than usual. "At most captain's runs, I kick maybe 20 balls. This time, I thought I'd kick four balls. It happened on the fourth. All this is pretty challenging, but I'm really lucky to have some great people around me. I hope to get over it and start thinking positively so I can help the guys out wherever I can."

Carter seemed relaxed enough: there was even the odd flashing smile. "I'm a little different behind closed doors," he confessed. "Last weekend, I had the craziest day of my life: I'd been made captain of the All Blacks for the Canada game, which was special, and then had it taken away from me. It was tough, having to phone the people who are really close to me because I didn't want them to read about it in the papers, but being around the team since then has spurred me on to be positive."

Cruelly, he will not be around the team as much as he would like once his replacement in the hosts' 30-man squad, the Manawatu stand-off Aaron Cruden, arrives at the team hotel. "I'll have to hand back my accreditation," he explained, a little sadly. Not that Cruden is likely to play much rugby – or, indeed, any rugby at all – in what is left of this World Cup. Carter's understudy, the inexperienced Colin Slade, is the man with the shirt on his back, although increasing numbers of All Black aficionados are wondering whether the scrum-half Piri Weepu might soon be deployed at pivot. Both Carter and Hansen had supportive things to say about Slade. "I felt sorry for Colin at the weekend because there was so much talk comparing the two of us, but I sent him a text telling him that he had an opportunity he should be excited about, and that he should make the most of it," said the injured man before Hansen added: "Colin Slade is Colin Slade. He doesn't need to be Dan Carter; he needs to be Colin Slade. It's a question of the other players doing their jobs that little bit better and take up the slack.

"We heard about the problem when Graham [Henry, the head coach] stood up and said: 'Dan's got a groin problem and it doesn't look good'. We looked at each other for a while and then got on with it, which is all you can do. As Dan says, it's gut-wrenching: certainly, it's not easy for him to come here and answer these questions. But he'll return from this stronger and tougher because he's a top bloke. I can see him playing in the 2015 World Cup because he'll be that much hungrier."

McCaw is confidently expected to take his place in the back row against the Pumas – "If the Canada game had been a quarter-final or a semi-final, he'd have played," Hansen asserted – and the coaching staff are increasingly confident that Kieran Read, the outstanding Canterbury No 8 who missed the start of the tournament through injury, will come through this week's training successfully after returning to active duty at the weekend.

Meanwhile, the injury-riddled Wallabies are slowly putting body and soul back together ahead of this weekend's supremely challenging last-eight tie with South Africa, the reigning champions, in Wellington. Having lost a number of players to a series of orthopaedic calamities – the wing Drew Mitchell, the centre Pat McCabe and the back-row forward Wycliff Palu are all out of the competition, while the midfielder Rob Horne is nursing a busted cheekbone – they believe one of their most influential backs, Digby Ioane, will be available after suffering a broken thumb in the opening-round victory over Italy.

Australia have won five of their last six matches against the Boks, but their captain James Horwill is reluctant to read anything into that run of success. "World Cups are different," he said yesterday. "It's tournament rugby now, knock-out rugby: it's a different kettle of fish and you can forget all the history."

South Africa, who are slowly recovering after finding themselves on the painful end of a ferociously physical assault by Samoa four days ago, consider themselves to be underdogs this weekend, for precisely those reasons Horwill was keen to dismiss.

"We haven't beaten them this year and last year wasn't too good either," admitted their skipper, John Smit. "I'm pretty sure they have a mental edge on us."