Time was, and not so long ago, when Steve Borthwick and Geoff Parling were squaring off against each other at lineouts, Borthwick at Saracens, Parling for Leicester. In the early 2010s the clubs were often drawn together in the playoffs – there were a couple of finals in 2010 and 2011, a semi in 2012. “Humdingers,” Parling says now.

A decade later, they will be at it again at Twickenham on Saturday, as coaches this time. Borthwick, of course, with England, and Parling with Australia, where he works as Joe Schmidt’s right-hand man.

They’re similar sorts, plenty tough, but soft-spoken and studious, too. It was Parling who took on Borthwick’s role as the brains behind England’s lineout in their playing days, and you guess they would be happy to stay up talking to each other about plays, patterns and calls long after everyone else at the table had gone to bed.

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But Parling’s role with Australia is bigger than that. He has been living there for almost seven years now after moving to play for, and then coach, the old Melbourne Rebels. His old friends say he’s picked up just a hint of an accent. He did a short stint with the Wallabies under Dave Rennie, before Eddie Jones came in and ripped everything up during his tumultuous seven-month stretch as head coach in 2023. Schmidt rehired Parling this year, to help him rebuild the national team before next year’s British & Irish Lions tour, and their home World Cup a year later.

“I think when you’re invested in something, it feels like the biggest thing in the world,” Parling says. “We’re under no illusions that next year’s Lions tour and the home World Cup are big projects for a country. So we’ve got to do our best to make sure we put our best foot forward and make sure we’re competitive so we can win some games there.”

They have three things going for them. One is Schmidt himself. The other is that, unlike Jones, he has the full support of the small, but passionate, rugby community in Australia. “Everywhere we go, there’s goodwill from people.”

And the last is that, even on their uppers, Australia have a lot of good footballers to pick from. “There are some great athletes and great players in Australia. In general, I feel like the population there is more athletic than the population here. I don’t know whether it’s because they’re being brought up on an outdoor lifestyle. The question is can we put them all together? That’s our challenge as coaches. It’s exciting. It’s a great challenge. It’s hard at times, but I do certainly think we’ve got some bloody good players.”

The latest is 21-year-old Joseph-Aukuso Suaalii, who has just come across from the National Rugby League on a three-year deal worth over £3m. “He’s looking good, I’ve been really impressed with him,” says Parling. “He’s an incredible athlete. I was watching him talking to himself in training, making sure he learned the calls, so I couldn’t be more impressed with how he’s applied himself so far.”

Parling played alongside Sam Burgess in the days England tried to shoehorn him into their backline before their own home World Cup in 2015, but he insists the two are very dissimilar. “I do feel it’s slightly different to Sam, because Joseph played union at school. He’s got a decent union background, and he’s younger than Sam was. There’s a lot of different factors behind it, if you have a union background – the age you are when you come across, what position you’re in. But I’m sure wherever he plays, he’s going to do well.” Sua’ali’i hasn’t played a professional match in union yet and Parling wouldn’t be drawn on whether that will change on Saturday. “Obviously we want to play him when we think he’s ready.”

If Suaalii is picked, he would be their 17th debutant this year. “We’re still finding out about some of these players,” Parling admits. “Some of these guys that are just starting to get exposed to their Test rugby.”

They’re going to learn a lot about themselves against England, when the Wallabies are clear underdogs against a team they’ve beaten once in the nine years since Parling finished his own international career. He has been back to Twickenham on only one occasion, as a spectator, since, so this will be his first time on the turf there since he started in England’s 33-13 defeat by Australia in the pool stages in 2015. He’ll be the one English person among the 80,000 at the ground who hopes this game ends up the same way.