Lealiifano was invited into Wallabies camp this week for the first time since the 19-Test playmaker's leukaemia diagnosis in August 2016.

He underwent chemotherapy and had a bone-marrow transplant before making a return for the Brumbies less than 12 months later.

The 31-year-old has returned to his best form this Super Rugby season, leading led the Brumbies to the top of the Australian conference with four games to play.

Lealiifano knew he was getting back to his best but admits he was still shocked when Australian coach Michael Cheika invited him back into camp.

"I was surprised. I wasn't expecting anything like that, my main focus has been here at Brumbies and I'm really enjoying it," Lealiifano said.

"I'm really proud of the journey I've been on over the last few years to be able to get that recognition, obviously late in my career as well, to still be recognised is a proud moment.

"I was stoked to be there."

Lealiifano was one of four playmakers in camp and will compete for a World Cup berth against NSW's Bernard Foley, and Melbourne duo Matt Toomua and Quade Cooper.

The Brumbies skipper said he wasn't getting ahead of himself, with the disappointment of missing out on the 2015 World Cup still fresh.

"I know you can get so close and still miss out so I'm wary of that and not to get too excited but it is a little bit real now," Lealiifano said.

"If you keep playing well you'll hopefully be in and round that team so that's my main focus, to continue the momentum we have here at the Brumbies."

Brumbies coach Dan McKellar believes Lealiifano is back to peak physical condition and the No.10 revealed doctors were thrilled with his health.

"I definitely feel like I'm playing as good as I have since I was sick," Lealiifano said.

"Last year I probably felt as good as I could have but still battled a bit and my playing probably showed that. I couldn't do what I wanted to do on the field but being out there was an accomplishment enough.

"It took a while to get me back to where I was pre-illness but speaking to the specialist they said you wouldn't know that I had leukemia with all my blood results.

"That's given me a lot of confidence to be able to run and do gym and get me back to full strength. I feel I am back and feeling really fit and raring to go."

Australian Associated Press