Wallabies: Taniela Tupou's rise as seen by his schoolboy mentor

Taniela Tupou is the former New Zealand schoolboy star who now finds himself at the forefront of Michael Cheika's Rugby World Cup plans, but the coach who helped to shape his development never had a doubt that he would one day crack the big time.

The 22-year-old front-rower debuted off the bench in last year's embarrassing 52-28 loss to Scotland, but that was the final Test of 2017, on the other side of the world in Edinburgh, so his selection this time around in Cheika's Wallabies squad to face Ireland will garner far more attention.

Just four years after he made the decision to move to Australia and join Queensland Reds, Tupou is already proving himself a key part of Brad Thorn's Ballymore revival. It's a rise that has come a tad earlier than expected, and one that some rugby judges questioned from the outset. But that thought never crossed the mind of Tupou's First XV coach at Auckland's Sacred Heart College, Gus Leger.

"I think he was always going to be [something special]," Leger tells ESPN.

"Look at him, he's an absolute freak.

"Because he was in the hostel [school boarding house] and I work in the hostel here, you could see that he was a physical presence.

"But another thing that was cool about him was he was also a gentle giant as well; he was really that cuddly bear that you had in and amongst the group that all the kids could jump on, and he'd just laugh when he'd have six juniors on his back. He bought into the program."

Originally spotted as part of a Tongan Rugby Union development tour to New Zealand, Tupou shot to fame at Sacred Heart. Back-to-back hat-tricks in Auckland's 1A competition, from a prop to boot, saw YouTube vision spread like wildfire and quickly established him as one of the hottest young properties in the game.

Tupou was already settled at Sacred Heart when Leger arrived, but the coach's first glimpse of a destructive free-running 'Nela' remains as vivid as ever.

"My introduction to Nela was in my first year, we played against Scots College down in Wellington," Leger tells ESPN. "We had a little tour there. We used to go to a quad tournament in Wellington; it was ourselves and a few other Catholic schools.

"But in this particular instance we had organised with Scots College to play them, and, unfortunately for Scots, Nela ran about 80 to 90 metres on one carry; that was pretty much the intro to Nela [that Leger had]. That was his little intro for us as a program, and I guess the rest is history."

As the hype continued to grow and Super Rugby and NRL clubs, on both sides of the Tasman, began to circle, the need to shelter Tupou from the media became apparent. Leger says Sacred Heart learned a lot about managing the weight of expectation on today's schoolboy stars through that period; they learned also about the lengths the media would run to in order to get their story.

Leger says the global attention never affected Tupou's personality, attitude or training ethic, the coach citing one preseason as proof. "We tried to keep everyone safe," Leger says of the media attention. "He was able to just get on with his work, and he trained the house down. He was a good trainer.

"I'll tell you a story: We go to the beach for our preseason up north, and guess who won the beach sprints out of the whole team? We're talking wingers, locks, loosies, the whole shebang. No-one could beat Nela. That much weight, that much power, beat our skinny little white boys that are 100m sprinters on the beach. He cleaned them up."

Known for his speed and raw power in the loose, the big question mark on Tupou was whether he had the scrummaging skills, or could at least develop the set-piece strength, to match. Leger says that was never going to be an issue, noting that Tupou was actually an excellent scrummager at school alongside Sosefo Kautai, who now plays for the Chiefs.

Putting it bluntly, the Sacred Heart First XV coach says: "We didn't go backwards much."

But Tupou's scrummaging skills have flourished under All Blacks great and now Reds coach Brad Thorn this season, and he worked over experienced Highlanders loosehead Daniel Lienert-Brown last weekend. The week before, Tupou showed off his speed in a sensational run down the sideline against the Hurricanes, laying on a try for Reds winger Jordan Petaia.

Whether his development is enough to see him usurp veteran Wallabies tighthead Sekope Kepu will be revealed in a week, when Cheika names his team for the first Test against Ireland in Brisbane. No matter the decision, Leger sees it as a "changing of the guard" for two New Zealand-schooled props; a process, incredibly, he has been a part of with both players.

"It's just that saying of 'time in the saddle'; especially for front-row and knowing that it's a profession and it's a specialist profession up front," Leger says of Tupou's development at the Reds.

"And he seems to be getting better and better as he sits in that level, that environment of the Super program.

"And with time, because he's still only young, he'll establish himself and one day fill the void of Sekope Kepu. And I have a special bond with Sekope as well because I used to work at Wesley College, and Sekope's part of the Wesley family. So seeing it being handed over from one person that I know, to another person that I know; they're both good men and it would be quite cool if that transition is to happen knowing that Nela's ready to be a person who's going to treat that role as a long-term responsibility.

"But, yeah, two really good kids who have really earned their stripes. And both of them used to be No. 8s."

Leger continues to serve as a sounding board for Tupou four years after the prop headed to Australia, the 22-year-old front-rower often picking up the phone for a chat or dropping in should rugby take him back to Auckland.

Can Leger bring himself to support the Wallabies, then, should Nela run out in the gold No. 3 jersey in a bit over a week's time?

"Always supporting Nela," Leger says.

"If he just happens to be wearing a Wallabies jersey, well then so be it. But person first; wherever he's going to be playing, we're always going to be supporting Nela."

A brief pause follows.

"That's a pretty politically correct statement, eh," Leger chuckles.

"We love Nela and we always make sure that he plays his best and he stays safe. He's a good kid, mate, and we're always going to support the boys that we've had something to do with."

A friendship for life. Until the 'Tongan Thor' brings the hammer down on the All Blacks, at least.