Giteau has spent more time as a soccer dad than a rugby player in the past four months after moving back to Canberra, and is having the longest break of his career to be refreshed for another season in Japan.

He admits he doesn't know how long he will keep playing, but the 35-year-old isn't interested in a farewell tour or sentimental moments as he prepares to play against the ACT Brumbies on Sunday.

Giteau opened up about his future, Quade Cooper and his glittering career before returning to Suntory.

Giteau made a low-key decision to retire from international rugby, calling time on his Wallabies career after 103 Tests and 16 years after his debut in 2002.

"When I got injured in that Bledisloe Cup game [in 2016], without saying it, I felt that was it," Giteau said.

"I was obviously really grateful for the experiences and opportunities I got through international rugby. I think there was just a time in my mind where I knew that was it."

Giteau has won titles in Australia, France and Japan as well as boasting plenty of Super Rugby and Wallabies highlights.

But that doesn't mean he's ready to walk away from playing duties. He has one-year left on his contract with Suntory in Japan and could extend that if he feels the desire to continue into 2019.

Time away from the day-to-day rugby environment has helped reignite his passion after helping Suntory win the Top League title last season. He says he still has "the desire to win all the time".

"I feel good and rejuvenated, this is the longest break I've had and four and a half months is a pretty significant time," Giteau said.

"Whether it's my last year or not ... it's not something I'm thinking about. I didn't think about it last year, either. You just do what you can, train as hard as you can and have as much fun as you can.

"I'm not super sentimental that way. At the moment I'm enjoying competing. But I wouldn't trick myself, I wouldn't play for the wrong reasons. If I'm not enjoying it any more, I have no problem saying this is my last year and that I've had a good ride."

The Brumbies will play against Suntory in an exhibition match this week, with the contest to double as an important pre-season test for the defending Japanese champions.

Former Brumbies skipper Giteau left the club at the end of the 2011 season after signing a lucrative deal with French giants Toulon.

He hasn't played with or against the Brumbies in the past six years and although there's no end in sight for his career, it's a fitting match to come full circle.

"It will be a good test. It will be a good opportunity to get us ready for the season," Giteau said.

"It's also a great opportunity for young guys in Canberra, guys to experience something new. I'm looking forward to it and it would be great to get the chance to play against [Christian Lealiifano] again. There might be some cheap comments out there."

Giteau, wife Bianca and children Levi and Kai have set up a base in Canberra for life after rugby and in between seasons.

"Coming back here ... it emphasised how much I've missed Canberra and how much I love this city," he said.

"The kids are in school and they're playing soccer so I've been on the sidelines for that. I know nothing about soccer ... but sport is sport and I just like that they're involved."

Giteau spent some time at Brumbies headquarters in his time off working with young players and coaches, as well as training by himself at Griffith Oval.

"If I don't want to compete, then I won't be there. That's the heart and soul of any sport, you've got to be competitive. You've got to want to do it. I hate losing. I love winning, but I hate losing," Giteau said.

The Brumbies are searching for another playmaker to add to their roster for the 2019 Super Rugby campaign and tried to lure Queensland outcast Quade Cooper to the capital this year.

Queensland and Rugby Australia is paying Cooper an exorbitant amount to play club rugby in Brisbane, and he's refusing to move despite interest from the Brumbies and Melbourne Rebels.

"It's such a waste [to not have Cooper playing Super Rugby]. If you think he's not the best No. 10, that's up to a coach.

"But the experiences and the places he's travelled, even if he's holding a pad [at training] he can say things to a kid to help them develop. It's the little things he could offer Australian rugby.

"I think it's such a shame that he's not playing. I've got no doubt [he could fit in at the Brumbies]. We had him at Toulon, he didn't play a great deal but he was so positive and he added as much as he could.

"I think he's one of the most talented players that we do have in Australian rugby. Even if you didn't think that, there's so much outside of that he could offer the starting XV."

Australian rugby lacks experienced playmakers at the moment. Could Giteau be lured into a comeback?

"I drew a line under Super Rugby in 2011. I was in that cycle for 10 years and mentally for me, it just wasn't exciting ... I didn't feel that competitive side."

MINATO RUGBY FESTIVAL

Sunday: Suntory Sungoliath v ACT Brumbies at Chichibunomiya Rugby Field, 1pm.