'I've seen the offer that Samu was given and it was a very, very good offer'

Wallabies' director of rugby Scott Johnson said Rugby Australia couldn't have done more to keep star centre Samu Kerevi.

The Queensland captain will play his final Super Rugby match on Saturday night against the Brumbies and play in Japan following this year's World Cup after knocking back a "very, very good offer", according to Johnson.

Johnson said Rugby Australia didn't want to lose a player in their prime and had done their best to keep the 25-year-old, who has played 23 Tests.

"Let's get it straight, the offer was good," Johnson said on Thursday.

"I've seen the offer that Samu was given and it was a very, very good offer that would have put him in the higher echelons of our country."

Johnson, who joined the Wallabies set-up from Scotland in March, said Kerevi's situation was "complex" and alluded to his extended family commitments.

"It's not perfect for him and for us and we understand there are issues away from the game for him.

"It opens the door for other players who we may be talking about in a different light in 12 months time."

Speaking at a Melbourne Rebels function, Johnson said he backed Rugby Australia's current policy of only selecting players who played Super Rugby or Test veterans with 60 caps who could be included under "Giteau's Law".

"I think the key component is that we have a responsibility to make sure our competition is the best in the world," he said.

"It's great to be able to control the player - their strength and conditioning and their skill development.

"We understand there are challenges but at the moment we think there's a nice mix of rewarding longevity."

Former Wallabies, Brumbies and Rebels captain Stirling Mortlock said the game was being wrecked by the loss of players such as Kerevi and the self-interest of Super Rugby clubs.

"It's a massive challenge and if we don't get our house in order in four years time we will have to change the eligibility rule because you might have a lot of players not in Super Rugby,' Mortlock said.

"It baffles me that we still haven't got our house in order with everyone pulling in the same direction.

"We've got still different factions in different areas looking after their own backyard and that's what's stifling us.

"The New Zealand model is all about creating great All Blacks and everyone club and player knows that but it doesn't happen in this country."