But Larkham, a Wallabies and Brumbies great, said Australian rugby should investigate a way to allow experienced players to boost their earning capacity overseas without losing the right to play Tests.

The Brumbies have secured their core Wallabies for the coming seasons with Matt Toomua, Christian Lealiifano, Nic White, Scott Fardy and Jesse Mogg all committing to new deals before the clash against the Free State Cheetahs on Sunday morning (Australian time).

Wingers Henry Speight, Joseph Tomane and powerful No. 8 Fotu Auelua are also in talks about their futures in Canberra.

There are fears there will be a mass exodus of Australia’s best players after the World Cup next year with cashed-up Japanese and French clubs ready to offer big-money contracts.

"The money on offer [in Europe and Japan] will draw some guys over there," Larkham said.

"But the World Cup is the holy grail of rugby … when I was coming through it was the Bledisloe Cup and Tri-Nations, but the World Cup has grown.

"We’re lucky to have a good group of players who are here for the right reasons; they’re passionate about the Brumbies and Australian rugby. [But] I look at some of the provinces and think those guys aren’t there for the right reasons."

The Brumbies face another signing challenge next season when more stars face the decision to stay in Australia or move their careers abroad. Fardy and Mogg signed one-year extensions while Wallabies Stephen Moore, Ben Alexander and Pat McCabe’s contracts end after the World Cup in England.

Former Wallabies captains George Gregan, George Smith and Stirling Mortlock have all backed the idea of a sabbatical to keep players in Australia.

Under the current ARU rules, players must be contracted to Australian Super Rugby franchises to be eligible for Wallabies selections.

New Zealand allows players – including Richie McCaw and Dan Carter - with 75 Test caps or more to go on a sabbatical and return the following season.

"For me, playing rugby was a chance to represent my country," Larkham said.

"But there comes a time in your life where you have to make a decision for the future.

"The beauty of rugby is that it’s a world game. I think the way New Zealand does a sabbatical works well for them and it could work well in Australia.

"But you’ve got to do your time in Australia first before you earn the right to go."

Brumbies skipper Ben Mowen has signed a deal with French club Montpellier, while Andrew Smith and Ruaidhri Murphy will play in Ireland next year.

Speight is close to a new deal with the Brumbies while Tomane wants to stay in Canberra but is still negotiating his future.

Larkham is in his first year as a Super Rugby head coach.

He retired from playing in 2011 and played more than 100 Tests for the Wallabies and more than 100 games for the Brumbies.

The Brumbies are at the top of the Australian conference but need to keep winning to maintain their standing.

Larkham admitted the pre-season was disjointed with coach Jake White quitting halfway through a four-year contract, chief executive Andrew Fagan resigning and the club moving its headquarters from Griffith to Bruce.

Larkham has also been juggling the Brumbies’ $4.5-million salary cap and a host of off-contract stars.

"I think in the future we’d like to have more [contract negotiations] done in the off-season," Larkham said.

"It has been a heavy workload … you expect it to be, but the shock was coming out of rugby as a player to being a coach and to do the job properly you have to spend a lot more hours at your desk to make sure things are right."