The Canberra-born prop has been called into New Zealand's extended touring squad in the likelihood he will play his first Test against Japan on November 3.

The 127 kilogram scrum weapon has been tearing teams apart in the New Zealand provincial competition after he made a decision to play across the Tasman rather than in Australia.

His All Blacks rise has been impressive for the 22-year-old son of former Canberra Raiders hardman John Lomax, and the Wallabies and ACT Brumbies will be lamenting one that got away.

The former St Edmund's College and Tuggeranong prop had a Brumbies training squad contract before the Melbourne Rebels swooped and offered him a chance to play Super Rugby.

He was on the Wallabies' radar, but the All Blacks were also watching closely and Lomax decided to move to Dunedin to link with the Otago Highlanders. So now the Brumbies junior and an Australian under-20s player of the year in 2016 is helping the enemy.

Lomax played rugby league like his Raiders enforcer dad until making the switch at St Edmund's, and his parents joke he picked the downstairs bedroom at home because it was the closest to the fridge.

"All I had to do when he was younger was to make sure the fridge was full. He was downstairs, which was pretty close to the kitchen and there were nights we could hear that fridge opening," John Lomax laughed.

"We're overjoyed, so proud of him. He was always a big kid. You could see he had some development in him, but he had a lot of physical attributes that could take him to a good level in rugby union."

Lomax's rise comes as the Brumbies prepare to unveil the last man on their roster on Tuesday, with the club expected to announce prop Vunipola Fifita has signed a full-time contract.

Fifita, who played alongside Lomax in the Australian schoolboys and under-20s team, moved to Canberra this year to join the Canberra Vikings for the National Rugby Championship.

His deal will complete the Brumbies' roster for the 2019 season after coach Dan McKellar finished his smart recruitment drive, which also includes the arrival of Queensland veteran James Slipper.

Lomax is preparing for a different challenge and his form for Tasman has helped launch his All Blacks career.

Tasman will play in the first week of the finals this weekend after winning nine of their 10 games so far, with Lomax demolishing his opposition props.

"He took on a challenge by going to New Zealand, but he's taken a lot of steps to get where he is and we're over the moon that he's been rewarded for making those sacrifices," John Lomax said.

"He made those decisions himself. We were just going to support him with whatever he did, and that goes right back to when he went from rugby league to rugby union.

"That's why I give the kid a pat on the back because he's pretty smart and coach-able. He takes a lot in ... and I'm happy for him and proud of him."

Former Brumbies under-20s coach Russ Ingram added: "He was dominant in his age group because of his size, and he was always going to be a front-rower.

"He had the perfect shape for a tighthead prop and it was just about teaching him. It's great to see him where he is today and the opportunity he's got."

All Blacks squad for the Spring Tour

Forwards: Dane Coles, Nathan Harris, Codie Taylor, Owen Franks, Nepo Laulala, Joe Moody, Karl Tu'inukuafe, Ofa Tuungafasi, Scott Barrett, Brodie Retallick, Patrick Tuipulotu, Sam Whitelock, Vaea Fifita, Dalton Papalii, Kieran Read (C), Ardie Savea, Liam Squire, Matt Todd.

Backs: TJ Perenara, Aaron Smith, Te Toiroa Tahuriorangi, Beauden Barrett, Damian McKenzie, Richie Mo'unga, Ryan Crotty, Jack Goodhue, Anton Lienert-Brown, Sonny Bill Williams, Jordie Barrett, Rieko Ioane, Waisake Naholo, Ben Smith.

Additional 19 man squad to assemble ahead of the All Blacks' Test against Japan on November 3

Forwards: Asafo Aumua, Liam Coltman, Tyrel Lomax, Reuben O'Neill, Tim Perry, Angus Ta'avao, Luke Romano, Jackson Hemopo, Gareth Evans, Dillon Hunt, Luke Whitelock.

Backs: Mitchell Drummond, Bryn Hall, Brett Cameron, Ngani Laumape, Matt Proctor, George Bridge, David Havili, Nehe Milner-Skudder.