The Ospreys openside, who once balanced morning training with afternoons spent labouring as a roofer, will win his first international cap as part of a Wales side featuring five changes from the scrappy victory over Japan.
A late penalty sealed that 24–23 win, but head coach Steve Tandy has turned to new energy and experience for the challenge of the All Blacks.
Deaves, 24, first entered the Ospreys system after emerging from his hometown club, Pontyclun.
Before rugby became his full-time career, he briefly pursued civil engineering at Bridgend College, only to refocus on his ambition to play professionally.
Early days in Swansea involved sharing training facilities with established Lions such as Alex Cuthbert, Justin Tipuric and Rhys Webb — before driving away in his van to pick up tools for roofing jobs.
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Tandy was full of admiration for the flanker’s journey and impact.
“Harri Deaves making his debut I think is an amazing story,” the Wales coach said.
“His performances for the Ospreys, both sides of the ball, have been outstanding. I love how he plays the game.
“He’s a smaller rugby player and the way he plays he adds physicality. His speed and aggression are there for everyone to see.
“It’s an amazing opportunity for Harri and we can’t wait to see him go on Saturday.”
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"I think it's more than just plugging away. He’s produced performances.
When you look at the start of the season and when the Ospreys went to South Africa, people talk about size but the way he pitched in was outstanding.
"He’s got lots of skill and packs a punch. I love the way he’s come into the environment. He ain’t going to die wondering. The way he plays, he’s very aggressive. He backs himself.
"But also, the work behind the scenes, the time he’s spending on the laptops to get up to speed just in case the chance came along. When he got named, he was straight into training as if he’s been here for more than a week.
"He’s got a great personality. I think he adds something to the group.
"You could see what it meant to the team when he was announced.
"Even the conversations with the boys who weren’t in the squad initially. I spoke to Harry. It's just his drive. He was amazing taking the feedback on board.
"He was grateful to just have the conversation. That tells you something about the kid. He’s been a great personality.
"But, more importantly, the way he’s trained. You can see the intensity and accuracy he brings.
"What a story to go up against the All Blacks. Historically, what a team. And at home at the Principality. It’s going to be an amazing day for him, his family and the community."
Deaves forms a revitalised back-row combination alongside Alex Mann and Aaron Wainwright.
In the front row, Rhys Carre and Keiron Assiratti rejoin the starting XV, packing down with captain Dewi Lake.
Further back, there is a significant return at centre. Joe Hawkins plays for Wales for the first time since the 2023 Six Nations.
Hawkins left the Ospreys to join Exeter after that campaign but the switch ruled him out of World Cup contention due to Wales’ overseas-appearance rules.
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Tom Rogers also re-enters the side on the wing, covering for Josh Adams, who is suspended following his red card against Japan.
Fly-half Jarrod Evans — the match-winner last weekend — is again named among the replacements.
Tandy hopes the refreshed selection can deliver a more complete performance.
“We obviously want to improve the performance from Japan,” he said.
“I thought we had some outstanding moments against Argentina (in week one). We felt we would have liked to have improved more last weekend.
“It was obviously good to get the win, but we want to improve our own performance against a world-class opposition on Saturday.”
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New Zealand, meanwhile, have rotated heavily after their 33–19 loss to England.
Head coach Scott Robertson has made 12 changes to his matchday squad but dismissed any suggestion that the All Blacks are overlooking Wales.
Only captain Scott Barrett, flanker Simon Parker and Will Jordan — shifting from full-back to wing — remain from the side beaten at Allianz Stadium.
Senior figures such as Ardie Savea, Beauden Barrett and Codie Taylor sit out the Cardiff clash, with Robertson confident his squad depth can step up.
“We have a lot to play for this weekend,” he said. “We want to put on a performance that reflects the effort and pride we have put in.
“We do not underestimate the passion and resolve that Wales will bring and we know how organised, accurate and ruthless we need to be in return.”
The historical backdrop is stark: New Zealand have prevailed in the last 33 meetings between the two nations. Wales’ most recent triumph dates all the way back to 1953.
Still, the young Welsh squad — buoyed by new faces like Deaves — will attempt to defy those decades of dominance at Principality Stadium.
Wales: B Murray; L Rees-Zammit, M Llewellyn, J Hawkins, T Rogers; D Edwards, T Williams; R Carre, D Lake (capt), K Assiratti; D Jenkins, A Beard; A Mann, H Deaves, A Wainwright.
Replacements: B Coghlan, Gareth Thomas, A Griffin, F Thomas, T Plumtree, K Hardy, J Evans, N Tompkins.
