Eddie Jones admits Taniela Tupou has been found out by his Test rivals since arriving in a "blaze of glory", but believes the 26-year-old will still become the world's best tighthead prop at the Melbourne Rebels.
Tupou's shift to the Victorian Super Rugby Pacific club from 2024 on a two-year deal, after nine years at the Queensland Reds, was confirmed by Rugby Australia on Friday.
Recovering from an achilles tear, he has almost certainly played his last game for the Reds but is targeting a playing return in time for the World Cup in September.
While a loss at Ballymore, his new deal is a win for Australian rugby with Jones not needing to use up an overseas selection on a prop who had been considering a future in Japan or Europe.
New Wallabies mentor Jones would not reveal to AAP what he viewed as Tupou's weaknesses while coaching against him for England.
But he did acknowledge the man who arrived on the scene as a 17-year-old sensation had been slowed in recent years.
"That's not unusual for a young tighthead," Jones told AAP.
"They come in a blaze of glory, then people work out their strengths, take them away and you've got to work out how to become a better player again.
"But he'll be the best tighthead in the world; he can do things nobody else can and we have to give him every opportunity to be his best."
Jones said with a fit-again Tupou alongside the recently re-signed Allan Alaalatoa the Wallabies had an "extraordinary" front row.
"One hundred per cent he changes the team (if he's fit to play at the World Cup)," Jones said.
"Between him and Alaalatoa, the quality of 80 minutes we can get out of that position ... will be extraordinary.
"Who starts and who finishes (from the bench) will be horses for courses."
Tupou has played 47 Tests and 87 times for the Reds, long-time coach Brad Thorn hosing down any suggestion the pair had fallen out.
"I don't have a problem with Taniela; we have good chats ... years ago I actually played with him in two games," Thorn said.
"There's always all sorts of chat, all sorts of speculation, but this guy I care about.
"I wish him well and as a guy who, after seven years at the Broncs (in the NRL), went on to have a crack at rugby, sometimes you look for a change up and I hope that's a good one for him."
Tupou thanked Rugby Australia, the Reds and the Rebels, for whom he will be an on and off-field boost thanks to his talent and personality.
"I've made some great memories, met some lifelong friends and I'll be doing everything I can to help them be successful this year," Tupou said.
"I'm excited by the future of Australian rugby with a Lions tour on the horizon (in 2025) but my priority is to work hard on my rehab and get back on the field as soon as possible."
