UPDATE: Wallabies coach Michael Cheika has complete confidence that teenager Jordan Petaia will "rise up to the challenge" of starting at 13 against England on Saturday night while Will Genia and Samu Kerevi believe the teenager is on the verge of greatness.
Petaia will play 13 for the first time in Test rugby in one of a number of changes to Australia's lineup for Saturday's Rugby World Cup quarter-final against England.
The 19-year-old was confirmed as the team's starting 13 when the lineup for Saturday's quarter-final was officially announced on Thursday afternoon.
Cheika said he had seen enough from Petaia on and off the field to know he could handle the step up, regardless of his age.
"I wouldn’t be looking at the age of players at either end of the spectrum," he said.
"This is going to sound silly - you just go and play footy you know. Meet the challenges ahead of you, the obstacles.
"Yes, it’s going to be fast and aggressive and all that type of stuff and I know that lad will rise up to that challenge.
"I know it. I’ve seen it in him, so I know he will on Saturday."
Outside centre is nothing new for the 19-year-old - it's his preferred position and the spot from which he launched a stunning Super Rugby outing against the Highlanders in Queensland's opening 2019 match.
Petaia's composure on and off the field is often discussed and Cheika reiterated that on Thursday, discussing Petaia's readiness for the task at hand.
"He’s just a good young rugby player. He’s pretty relaxed but he’s very well prepared," he said.
"That’s the one thing I’ve noticed about him, he gives off a demeanour of talk pretty cool and chill but he’s very well prepared both off the field in getting ready tactically and physically.
"He has been preparing himself for a long time, getting himself ready."
Halfback Will Genia, who returns to the starting team this weekend for the first time since Australia's match against Wales, said his aim since Petaia came into the group was simply to help him feel at home.
"I rate Jordan very highly, he's a player who could be one of the best players in the world in the not too distant future so I think personally I've just wanted to make him as comfortable as I can so that he can be himself genuinely," he said.
"Whether that's in training, off the field or, most important, on the field, I love seeing him express himself, and the more he does that, the more comfortable he is, the better he’s going to be for us as a team."
Petaia will be teaming up with the man he stood outside that night as well, with Samu Kerevi named at 12.
It was alongside Kerevi that Petaia played the match that had Australia's Super Rugby fans talking - a scintillating round 2 performance against the Highlanders.
A week later, Petaia suffered a lisfranc injury that ended his Super Rugby season, and seemingly put his Wallabies hopes on ice.
While it was that match that had fans' tongues wagging, Kerevi has been waiting for Petaia to truly be unleashed since the first day he saw the teen walk into Ballymore.
"I’ve had thoughts about Jordy since the first day he actually walked into our club at the Reds, the way he trained," he said.
"I think he just had that rare talent and now he's really refining that, becoming the player that he is.
"I think Cheik spoke about it a couple of weeks ago, he's still writing his own story, I'm really excited to see how he goes, not just for this weekend but the rest of his career.
"From the first time I seen him at training and the way he is, he's going to be one of the greats."
Kerevi said a move to 13 would give Petaia a chance to be more involved than he has so far in this World Cup.
"I think defensively he's pretty important, he's a really good defender," he said.
"I think for me just wanting to get the ball in his hands a bit earlier and just letting him go, letting him do his thing.
"That's what we want him to do from his first debut, give him ball with a lot of time and you saw that from the get go so I think more time with the ball in hand."
Henry Slade, the England centre who was himself something of a surprise selection at no.13, said he knew of Petaia but conceded his youth and Test inexperience could be a bonus for England.
“He has been picked in the squad because he is a bloody good player and I don’t know if that plays such a big part now because everyone in these squads are top players and don’t get affected by things like that, but if it is a thing then it will probably help us,” Slade said.
Petaia's shift to the centres comes with the return of Reece Hodge to the starting side, a timeline the Wallabies have been conscious of since Hodge was suspended for three matches after their Fiji game.
Cheika said, though, that Petaia's move to 13 was not marked down at the start of the tournament or even weeks ago, rather a decision that the selectors came to after seeing his development.
“We didn’t sit back and earmark this game for him to come and play at 13," he said.
"We just watched the games and made the assessments of each player as they went along and there were things that we liked and what we seen from Jordan both on the field in games and also at training and we felt that this would be a game that would suit him.
"The guy’s been in around the squad for a while now even though he’s young, he’s more than ready to do this.
"The way his demeanour is you wouldn’t think he was picked, he was just loping around as per normal so it’s going to be great.
"I trust him infinitely and that’s why he’s been chosen."
Petaia is among six changes to the Wallabies' starting XV for this weekend's clash, four of those coming in the backline.
It's a string of changes that follows a pattern of chopping and changing for the Wallabies this tournament, with four backline changes, and 12 and 11 starting XV changes, respectively in their three previous pool matches.
Petaia is among six changes to the Wallabies' starting XV for the clash, with four of those coming in the backline.
Genia will team up with Christian Lealiifano in the halves for the first time since July's Brisbane Test against the Pumas, pushing Nic White to the bench.
Reece Hodge will start on the wing in his first match back from suspension with Kurtley Beale cleared of concussion to play at fullback.
Dane Haylett-Petty is the unlucky man left out of the 23 despite producing solid performances on the wing and fullback in recent weeks.
Allan Alaalatoa and Michael Hooper come back into the starting side after missing the Georgia match while Adam Coleman returns to the pine for the England match.
Taniela Tupou has been given the nod over veteran Sekope Kepu as reserve tighthead.
Kerevi's threat is clearly felt by England with the team they named on Thursday overwhelmingly geared to quelling his attacking influence.
Australia takes on England in their Rugby World Cup quarter-final on Saturday October 19, kicking off at 4:15pm local, 6:15pm AEDT, LIVE on Foxtel, Network Ten and via RUGBY.conm.au RADIO, Rugby Xplorer and Amazon Alexa.
Wallabies to play England
1. Scott Sio (62 Tests)
2. Tolu Latu (18 Tests)
3. Allan Alaalatoa (36 Tests)
4. Izack Rodda (24 Tests)
5. Rory Arnold (25 Tests)
6. David Pocock (82 Tests)
7. Michael Hooper (c) (98 Tests)
8. Isi Naisarani (7 Tests)
9. Will Genia (109 Tests)
10. Christian Lealiifano (25 Tests)
11. Marika Koroibete (27 Tests)
12. Samu Kerevi (vc) (32 Tests)
13. Jordan Petaia (2 Tests)
14. Reece Hodge (38 Tests)
15. Kurtley Beale (91 Tests)
16. Jordan Uelese (8 Tests)
17. James Slipper (95 Tests)
18. Taniela Tupou (18 Tests)
19. Adam Coleman (37 Tests)
20. Lukhan Salakaia-Loto (20 Tests)
21. Nic White (30 Tests)
22. Matt To’omua (51 Tests)
23. James O’Connor (51 Tests)