A shining light for D-Rocks in the Japan Rugby League One, Kerevi has featured in the past two global showpieces but not donned the Wallabies gold since starring in Australia's 52-20 rout of Wales on the 2024 spring tour.
But Genia reckons Kerevi, still only 32, remains a world-class force who could be deadly for the tournament hosts in 2027.
"You can imagine having someone like him at 12 and at Suaalii at 13. You've got size, you've got power, you've got skill, finesse and ability all packaged in one centre pairing," Genia told AAP from Japan.
"Because when I look at Test rugby, size matters. It's done a bit of a cycle now where ball in play isn't as high. The ball-in-play time, it's shorter, sharper bursts, which lends itself to bigger athletes and more power athletes than it used to."
An influential member of Australia's 2015 World Cup final line-up and the Wallabies outfit that finished third in 2011, Genia believes it's no coincidence South Africa and France are "probably the two best sides in the world right now".
"They use their physicality and their presence in the game to be able to win collisions and play on top of teams," he said.
"And so you can imagine having a team with a backline like Kerevi, Joseph, 'Marky' Mark (Nawaqanitawase). The size they would offer them and the impact they would have. That'd be awesome to see."
Genia's only caveat for a Kerevi recall to the Test arena is that he'd need to return to Australia for a full pre-season and intense lead-up to a World Cup next year.
"He's of that world-class calibre, but it's important to be playing Super Rugby," said Genia, who is serving as skills coach for the top-of-the-table Kintetsu Liners in Japan's League One division two.
"And I'm not saying Japanese rugby isn't quality rugby. It is. Just in terms of the intensity that you face week in, week out in Super Rugby is second to none.
"So you'd want him to have that intensity under his belt leading into a World Cup."
Genia has also thrown his support behind NSW Waratahs veteran Jake Gordon to remain the Wallabies' first-choice No.9 for the first World Cup in Australia since 2003, with Queensland pair Tate McDermott and Kalani Thomas to battle it out as Les Kiss's second-half finishers.
"Jake because he has a very good all-round game," said the 110-Test retired great.
"Your core roles for a halfback is passing, kicking, running and you'd say he's a nine out of 10 on every single one of them.
"So that matters because the margin for errors at that Test level are very small but he stands out on top of that because he's also got a point of difference, which is his ability to control the games where he's kicking.
"And he's been playing well consistently and been very good for the last couple of years."
While he also rates Brumbies half Ryan Lonergan for his goalkicking and leadership, Genia prefers McDermott and Thomas as Gordon's back-ups.
"Thomas is quite an instinctive player, quite similar to Tate, and he's had experience in that Wallaby environment now last year. He's he's got a great upside.
"So Kalani, his running game, his ability to be able to break the game open with his threats around the ruck.
"Yeah, so those three - Jake, Tate, and Killarney, most likely."
