Fifita, a close friend of Taniela 'Tongan Thor' Tupou, was announced as the ACT Brumbies final signing on Tuesday, with the former Australian under-20s prop to join the club's front-row rotation next year.

It's a massive turnaround for Fifita, who says he lost his passion for rugby when shoulder and hamstring injuries ruled him out for most of the 2017 season.

His weight ballooned to 141 kilograms and he was unsure if he had the desire to work hard enough to force his way into a professional squad.

But the birth of daughter Elenoa at the end of last year sparked his motivation and the 22-year-old is determined to make the most of his wider contract squad deal in Canberra.

"At the start of this year I just said I was going to have a crack and I went from there," Fifita said.

"I think everyone who goes through injury, they worry. After the [Australian] under-20s you're expecting something to happen, and I was definitely a bit worried.

"But I had a little one [Elenoa] come along and that opened my eyes a bit. It changed my life and everything around me.

"The injuries dragged me down a bit and put me through a really dark place I haven't been before. Everyone goes through that period with injuries, and I went downhill.

"I lost my passion a bit, I was just rocking up for the sake of it. I didn't want to play any more. I put on a lot of weight ... that's when I just thought I was going to play for fun."

"I wasn't expecting anything after that until the little one came along. I looked at her one day and said: 'yep, I'm going to have a real crack at footy'."

The softly-spoken Fifita, whose first language is Tongan, moved to the capital for a chance to play in the National Rugby Championship with the Canberra Vikings.

He'd never met or spoken to Brumbies coach Dan McKellar until the early weeks of the Vikings season after he had impressed on the field.

His performances opened the door for him to earn the last contract at the Brumbies and he will join a strong prop group which includes Allan Alaalatoa, Scott Sio and James Slipper.

Fifita shared a room with Tyrel Lomax when he was in the Australian junior teams and grew up with Tupou. Seeing Lomax be on the verge of an All Blacks call up and Tupou rise into the Wallabies has given Fifita confidence he can step up to Super Rugby.

"I was just coming here for the NRC, I was just happy for that. I didn't get any calls from any of the Sydney [NRC teams]," Fifita said.

"I said yes [to the Vikings] straight away, I was definitely going to come. It was an easy decision, and getting an opportunity to have a crack at Super Rugby with those guys to look up to.

"It's amazing to finally get a crack, I'm grateful for the opportunities the Brumbies have given me."

NRC SEMI-FINAL

Saturday: Fijian Drua v Canberra Vikings at Lautoka, Fiji, 3pm.