But the Brumbies mentor concedes the chance of Super Rugby AU's champions facing their counterparts from Super Rugby Aotearoa may be a bridge too far this year.

The coronavirus pandemic has left doubts surrounding the international calendar with Rugby Australia officials pushing ahead with plans to stage a Wallabies versus All Blacks Test series.

The Australian competition will run until September 19 with a final to be played at the home ground of the highest-ranked team - which, as it stands, is McKellar's Brumbies outfit.

New Zealand's iteration of Super Rugby is slated to end on August 16 with a first past the post system cancelling out the need for a finals series. The Canterbury Crusaders hold a two-point advantage over the Auckland Blues with two rounds remaining.

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Time constraints have raised the prospect of a champion versus champion match being played to open the 2021 calendar in similar fashion to rugby league's World Club Challenge, which pits the NRL premiers against their English Super League counterparts.

"All of those things need to be taken into account moving forward," McKellar said.

"Can we have a best of the best in the southern hemisphere post your own Super Rugby competitions? I think they're all things that will be considered.

"It'd be nice to see. You want to play against the best. The issue there may be in and around scheduling and time available between the end of both competitions and the start of the Test series.

"That's what will stop that from potentially happening. I know the New Zealand comp will finish a few weeks before us. It would be good to have but I doubt it will happen [in this calendar year] just because of time."

A playoff between each nation's champions could be considered as a potential competition model in the near future, as Australia and New Zealand officials map out a path for 2021 and beyond.

New Zealand Rugby officials have outlined their desire for an eight to 10-team competition featuring five Kiwi franchises and a Pasifika side. That would leave room for two to four Australian teams.

But Rugby Australia remain steadfast in the belief all five of its own Super Rugby franchises have a future beyond 2020.

A showdown between each nation's premier Super Rugby outfit could be a major drawcard as uncertainty hovers over the international calendar.

The prospect of a Bledisloe Cup series seems the most likely avenue for internationals to proceed across the Tasman at season's end. Hopes of a Rugby Championship including South Africa and Argentina are seemingly getting smaller.

SUPER RUGBY AU ROUND SIX

Friday: Melbourne Rebels v ACT Brumbies at Leichhardt Oval, 7.05pm.

Brumbies: 1. Scott Sio, 2. Folau Fainga'a, 3. Allan Alaalatoa (c), 4. Darcy Swain, 5. Nick Frost, 6. Rob Valetini, 7. Tom Cusack, 8. Pete Samu, 9. Joe Powell, 10. Bayley Kuenzle, 11. Andy Muirhead, 12. Irae Simone, 13. Tevita Kuridrani, 14. Solomone Kata, 15. Tom Banks. Replacements: 16. Connal McInerney, 17. Harry Lloyd, 18. Tom Ross, 19. Will Miller, 20. Ben Hyne, 21. Ryan Lonergan, 22. Mack Hansen, 23. Len Ikitau.

Rebels: 1. Cameron Orr, 2. Jordan Uelese, 3. Jermaine Ainsley, 4. Matt Philip, 5. Trevor Hosea, 6. Josh Kemeny, 7. Brad Wilkin, 8. Isi Naisarani, 9. Frank Lomani, 10. Andrew Deegan, 11. Marika Koroibete, 12. Matt To'omua, 13. Campbell Magnay, 14. Andrew Kellaway, 15. Reece Hodge. Replacements: 16. Efi Ma'afu, 17. Cabous Eloff, 18. Pone Fa'amausili, 19. Michael Stolberg, 20. Richard Hardwick, 21. Rob Leota, 22. James Tuttle, 23. Billy Meakes.