The Brumbies' season begins at Tokyo's Prince Chichibu Memorial Stadium against 2016 debutants, the Sunwolves.

The 208cm Arnold twins will become the tallest lock combination in history should they take the field together.

Richie joined the Brumbies, along with Chance Peni, Isi Naisarani, James Verity-Amm and Mees Erasmus from the Western Force after the Perth-based franchise were cut from the competition last year.

McKellar said Richie had earned his place in the starting XV on the back of an outstanding summer of training and trials.

It means 15-Test veteran Rory has been relegated to the bench, as Richie partners with Brumbies co-captain Sam Carter.

He will be joined on the pine by fellow Wallaby Blake Enever despite the latter debuting for Australia against England at Twickenham in November.

But the Brumbies boss said Rory would definitely see some game time against the Japanese team as he worked his way back to fitness.

"He'll play some good minutes. We had a good chat and he's coming back from injury and hasn't done a full pre-season so we'll slowly increase his time," McKellar said.

The Brumbies are not quite at full-strength, with Wallabies prop Scott Sio recovering from a minor calf strain back in Canberra.

Wallabies star David Pocock is out until at least the round seven match against NSW Waratahs, with 2016 sevens Olympian Tom Cusack getting the nod at openside flanker ahead of Lachlan McCaffrey.

The Force influence will be strong, as Richie Arnold is joined by Peni and Naisarani for their Brumbies debuts.

19-year-old Melbourne-bred Rob Valetini shapes as an exciting prospect in his first Super Rugby game, slotting into blindside flanker.

The firsts continue for the Brumbies with 41-year-old McKellar stepping into the job after Stephen Larkham took up a full-time assistant role with the Wallabies.

"I started coaching a long time ago and this is something I've always wanted to do so it is very exciting," McKellar said.

Co-captain and playmaker Christian Lealiifano will make his first Super Rugby start since 2016.

The playmaker made an inspirational return from leukaemia via the bench in last year's quarter-final defeat against the Hurricanes.

The Sunwolves won just three games in their first two seasons, including a 66-5 thumping by the Brumbiesin 2016 but should improve.

Brumbies: Tom Banks, Henry Speight, Tevita Kurdrani, Kyle Goodwin, Chance Peni, Christian Lealiifano, Joe Powell; Isi Naisarani, Tom Cusack, Rob Valetini, Sam Carter, Richie Arnold, Allan Alaalatoa, Josh Mann-Rea, Ben Alexander.

Res: Robbie Abel, Faalelei Stone, Leslie Leuluaialii-Makin, Rory Arnold, Lachlan McCaffrey, Matt Lucas, Whatenui Hawera, Lau

Australian Associated Press