Cubelli will go head to head with Brumbies coach and Wallabies attacking mentor Stephen Larkham when Australia play Argentina on September 16 in Canberra's first taste of Test rugby in seven years.

The Argentinian scrum half is eyeing a return in the June Test window against England after he ruptured his patella tendon in a pre-season trial against the NSW Waratahs in Mudgee.

Losing an experienced player like Cubelli was a massive blow for the Brumbies who are already without Stephen Moore, David Pocock, Joe Tomane and Matt Toomua.

Brumbies co-captain Christian Lealiifano is in remission after a successful bone-marrow transplant but remains unlikely to play this season.

The Brumbies have signed Southern Districts scrum half Dewet Roos on a two-month contract to cover for the 58-Test veteran's absence.

Roos will put aside his normal job as a construction project manager to feed Super Rugby scrums, where the he will jostle with youngsters Joe Powell and Ryan Lonergan for a starting spot.

The 26-year-old was overseas when he got a message saying 'don't get your hopes up, but they are looking at you' and Larkham eventually came calling.

South African-born Roos played for the Australian Barbarians against the Brumbies in a pre-season trial match after impressing for the Sydney Rays in the National Rugby Championship last year.

Roos has two months to press for an extension before the Brumbies prepare to welcome a Puma back into their ranks.

Cubelli is eyeing a Super Rugby return by the end of the season, which would hold him in good stead to force his way back into the Argentinian side for a clash with the Wallabies at Canberra Stadium.

While Larkham knows Cubelli's game inside out, the crafty number nine will have plenty of tips for his Pumas teammates in the lead up to September 16.

"We've played against Argentina with Tomas in that team for a couple of years now so I know the way Tomas plays but he also knows the way we play," Larkham said.

"There's a few things that we do at the Wallaby level that we've bought back here to the Brumbies that Tomas has picked up on.

"In fact, the first week [of training] he said 'Is that the way the Wallabies do it?' I said 'Yes, it is.'

"He's got a bit of insider trading, but I think we've seen a healthy rivalry between Argentina and Australia over the last couple of years irrespective of the insider trading."

Larkham inspired the Wallabies to a 32-25 victory over Argentina at Canberra Stadium in 2000, the second of four Test rugby matches at Canberra Stadium.

The Canberra Test will be a new beginning for Larkham after he finishes his dual-life as head coach of the Brumbies and the Wallabies' attack coach at the end of the Super Rugby season.

"It'll give me a good opportunity to focus on the attacking components of the Wallabies and not worry about the Brumbies campaign for the following year," Larkham said.

"I think I'll certainly be looking forward to that come the end of Super Rugby season, but at the moment certainly focused on making sure the preparation for this Super Rugby season is as good as it can be."

The Brumbies will likely begin the year without prop Scott Sio, who Larkham says is "highly unlikely" to play in the opening round against the Crusaders with a hamstring strain.

SUPER RUGBY ROUND ONE

February 25: Canterbury Crusaders v ACT Brumbies at Christchurch, 5.35pm.