With only 11 Super Rugby appearances under his belt, 19-year-old Jordan Petaia is in the Australia squad. In a group that has more caps than any previous World Cup squad, an average of 45 per man, he’s a bolter. Yet to get on the field and gain a cap – that will probably occur in the games against Georgia and Uruguay – he has been on everyone’s radar since his Brisbane State high school days. It is great to see and fills us with excitement that we may be witnessing the birth of a new rugby star. It also got me thinking. Where are the teen sensations? Are there any more beyond the very rare exception of the young Queenslander?

I remember coaching England Sevens when they faced a 17-year-old James O’Connor playing for the Aussies and he was full of risk and skill. He was to earn the first of many full international caps a few months later. Although he has put on a fair bit of bulk over the decade since, he was not the biggest then and I would question whether he would have got the opportunity so quickly if he was to emerge now.

Uruguay shock Fiji in World Cup thriller to pull off historic victory Read more

Petaia has no problems in the size department. At 6ft 3in and just under 100kg he uses his power to devastating effect and has a skillset that is excellent, too. However, without that physical presence to accompany the more subtle parts of his game, I don’t think he would have broken through so early. The mix of what is required has changed. You still need the foundation of core skills but on top of that an added level of physicality is needed that few teenagers possess.

One player that cuts across O’Connor and Petaia is Manu Tuilagi. Again, I came across him at age grade and managed to persuade the then director of rugby at Leicester Tigers, Richard Cockerill, to let me pick him for a run out with England Sevens as a teenager in the London Floodlit 7s. He was ridiculously powerful, but I was also impressed with his skills. He could really pass and had good game understanding, too.

It’s easy for us all to point the finger at the professional game and say it’s all about power over skill, running into a face not a space. It’s even easier to say that about a player who looks made to measure for that role. Often that is unfair and these days you simply need both to play at the very highest level.

The needle has swung more to the physical rather than the cerebral, and the way the game is officiated has fostered this, alongside the continued advances in players’ conditioning. After this World Cup, I hope World Rugby gets to grips with the ruck and the offside line and effectively de-powers and up-skills the requirements for a team to win phase ball. It has an opportunity to move the game away from Newton’s first law of motion and which if not addressed will mean by 2023 size will have increased in influence.

This gets compounded as the domestic game, to a large extent, moulds the players we produce. In England the Premiership has a level of physicality that is hard to ignore and that means for the majority of youngsters it’s going to take a bit longer to get to that point.

The Breakdown: sign up and get our weekly rugby union email.

Tom Curry and Joe Cokanasiga have those physical requirements and have hit international rugby hard – but they also possess high levels of skill and guile. Products of academies and the England age group system when John Fletcher, Pete Walton and Russell Earnshaw were still in situ, their all-round games were moulded and grown. Joined-up thinking – a rarity sometimes in the development of young players – was apparent and as we can all see, it worked. Would they be in this group if they were still teenagers? Possibly, but it takes me to the second reason for the lack of youngsters at this World Cup. Caps.

Back in my RFU days, the performance department was almost hysterical in its desire to build a squad around the number of collective caps. It would argue you had to have a certain amount of international appearances in a group to be real contenders. So the chance of a youngster breaking through declined.

USA coach refuses to bite after '15 Donald Trumps' remark by Eddie Jones Read more

Investment bias can also muddy the waters and a coach or management can become blind to evidence that contradicts initial selections. Players get kept in teams for too long because of that and younger players take longer to make inroads. It’s a skill to move players on at the right time, just as much as it is the same for players coming in and, twinned with the caps and the physical requirements, is the timing of their entrance in the cycle.

Next year I am sure we will see more youngsters blooded. Eddie Jones has already introduced a number into England training squads and he should be congratulated for that. The same will happen around the globe as teams start the long muster towards France 2023. With the international calendar as full as it is, a new player could get close to 50 caps in that four-year period. The quality of young players’ skill and game understanding is still, by and large, there. However, the number of boxes they will have to substantially tick has grown and with the interpretation of the laws as they are, the need for size has only increased this. Twenty-two is the new 18.

I’m gutted for Fiji

I’m just a little bit broken for Fiji after their defeat by Uruguay and I feel really sorry for their management in particular. Fiji had a short turnaround after Saturday’s opener against Australia and so had to use their full squad for this game. But they have known that for a long time. Currently their first-choice back row are all out injured, so they had to play second-row Leone Nakarawa at No 8, and that didn’t help either. I was at the game in November when Fiji played Uruguay at Hartpury College and it was one-way traffic in a 68-7 win for the islanders. So I can see a mix of short turnaround and injuries over complacency and poor kicking didn’t help Fiji in Kamaishi, set against the energy and passion and tactics that brought Los Teros all the 50/50s. It’s brilliant for Uruguay but the defeat pretty much kills off Fiji’s chance of a quarter-final place and makes their game against Wales far less alluring, especially if Warren Gatland’s side beat Australia.