Keen to stay ... Matt Toomua.

Matt Toomua. Photo: Karleen Minney

Stephen Larkham will resist the temptation to experiment with incumbent Brumbies five-eighth Matt Toomua at inside centre, despite his breakthrough Wallabies season in the No.12 jumper.

Toomua was a revelation when put outside five-eighth Quade Cooper during the spring tour, making the spot his own in just four games after injury to Christian Lealiifano.

The temptation to test Toomua as a play-making foil outside Lealiifano, as he was for Cooper, will be there for Larkham in the season ahead given Lealiifano's similar versatility.

Brumbies coach Stephen Larkham.

Brumbies coach Stephen Larkham. Photo: Rohan Thomson

Following a season-ending injury to Toomua in 2012, Lealiifano excelled at No.10 and was named man-of-the-match in eight of the 10 games he played that season.

But Larkham has no plans to tinker with the combination that helped take the Brumbies to last year's Super Rugby grand final, especially given that Lealiifano will miss the first three to five matches of the season because of ankle problems.

''It worked really well for us last year, having that combination of Matty at 10 and Christian at 12,'' Larkham said.

The Brumbies will play their last trial match against an ACT XV at the Royal Military College, Duntroon on Friday night.