The Melbourne Rebels pivot will reach his 100-game milestone where it all began when he runs on to Canberra Stadium on Saturday night to play against the club that launched his career more than a decade ago.

Back then To'omua was the young 'Pup' eager to learn off some of Australian rugby's best talent and prove he could match it with them.

Now he's on the other side of the fence - the wily veteran going toe-to-toe with rookie Noah Lolesio, who admitted to not knowing whether to tackle To'omua or ask for an autograph.

But both are vying for the Wallabies' No. 10 jersey, with new Test coach Dave Rennie adding six-game flyhalf Lolesio to an extended players of national interest squad.

"I think he's been great," To'omua said of Lolesio. "Against us in round two, it was probably one of his better games. Fair play, they outplayed us [as a team] and he outplayed me in that game.

"Me being a part of the Brumbies for so long and then seeing him develop ... they develop their players right, particularly in that position.

"He doesn't play a role where there is heaps of pressure mounted on him. He plays his role very nicely and then attacks when he needs to. It's a really good development example for young halves.

"He fits a part of the system and you can see that. That's the Brumbies system working really well and allowing the guy to develop and he's done it well. It's exciting from an Australian fans point of view, and from my point of view there's some competition there. It's exciting times to have that.

"Eight months ago we probably thought there was a huge void [at flyhalf], but it's starting to look a bit healthier."

The coronavirus shutdown has given To'omua, the youngest player to debut in Brumbies history, a chance to go back to where it all started this week, beginning the new competition with a trip down memory lane.

"It's been a wild ride. Coming back to Canberra makes it all a bit more real going from when I was very, very young and saw the world a different way," To'omua said.

MORE CANBERRA SPORT

"I spoke to a few of the young guys, it is exciting. Hopefully I've got a few more left, but you can't help but be a bit reflective. I'm quite thankful with all the opportunities rugby has given me.

"I still remember my first year sitting next to Stirling Mortlock in business class [on a flight] and I didn't sleep a wink because I was terrified of him ... he's an odd cat. I'd love to make sure the game's in a healthy state to give the same opportunity to others."

Lolesio has stepped into the Brumbies' No. 10 role this year, filling the role Christian Lealiifano and To'omua shared for most of the past 12 years.

The 20-year-old showed remarkable composure in the opening games of his career, throwing sublime flick passes to set up tries and being unfazed by making mistakes.

"We keep him grounded," Brumbies coach Dan McKellar grinned. "He's at the start of his career. Great players aren't made off the back of half a dozen games.

"But he keeps himself grounded ... he's got a work ethic and an attitude where he just wants to keep getting better and better every day. He's had some learnings as well, he knows he's just getting started.

"He's had a good block to work on his individual game, understand he belongs at this level and he'll be ready to start again."

SUPER RUGBY AU ROUND ONE

Saturday: ACT Brumbies v Melbourne Rebels at Canberra Stadium, 7.15pm

Brumbies: 1. James Slipper, 2. Folau Faingaa, 3. Allan Alaalatoa, 4. Darcy Swain, 5. Murray Douglas, 6. Rob Valetini, 7. Tom Cusack, 8. Pete Samu, 9. Joe Powell, 10. Noah Lolesio, 11. Tom Wright, 12. Irae Simone, 13. Tevita Kuridrani, 14. Andy Muirhead, 15. Mack Hansen. Reserves. 16. Connal McInerney, 17. Scott Sio, 18. Tom Ross, 19. Tom Cusack, 20. Lachlan McCaffrey, 21. Issak Fines, 22. Bayley Kuenzle, 23. Len Ikitau.

Rebels: 1. Matt Gibbon, 2. Jordan Uelese, 3. Pone Fa'amausili, 4. Matt Philip, 5. Michael Stolberg, 6. Josh Kemeny, 7. Richard Hardwick, 8. Michael Wells, 9. Ryan Louwrens, 10. Matt To'omua, 11. Marika Koroibete, 12. Billy Meakes, 13. Reece Hodge, 14. Andrew Kellaway, 15. Dane Haylett-Petty. Reserves: 16. Efitusi Maafu, 17. Cameron Orr, 18. Jermaine Ainsley, 19. Trevor Hosea, 20. Esei Haangana, 221. Rob Leota, 22. Frank Lomani, 23. Andrew Deegan.