The Australian Rugby Union is confident it can fend off a raid from the NRL and lock in dual international Israel Folau for up to three years thanks to a new flexible contracting model to be announced within the month.

Speculation mounted within minutes of news on Wednesday that the 2013 premiers had lost Kiwi international Roger Tuivasa-Sheck to the Warriors that the Roosters may make a play for the former Origin and Kangaroos representative, who is off contract at the end of this year.

The Roosters would presumably have to avail themselves of NRL boss Dave Smith's much-talked about war chest to plug the gap between 21-year-old Tuivasa-Sheck and Folau's current salaries, but the Waratahs fullback remains a prime target for the code that blooded him more than eight years ago and watched him slip away, twice, to the AFL and rugby.

Folau will also attract interest from overseas rugby markets such as Europe and Japan. But the advent of so-called flexible contracting in Australian rugby has the ARU hopeful that it can retain its most marketable player for up to three years in a deal structured so that Folau can play in Japan between Test and Super Rugby seasons.

Wallabies coach Michael Cheika refused to comment on the detail of negotiations between the ARU and Folau's management but said he was confident the 29-Test fullback would wear a gold jersey beyond this year's World Cup.

"Israel is going really, really well, he's having a great year and enjoying playing up front a bit with the Waratahs, and I'm really confident that he's enjoying his rugby and he's going to want to stay here," Cheika said.

"Everyone knows what everyone wants, it's just a matter of finalising a few bits and pieces. [Folau's manager Isaac Moses] is someone who is very professional and wants to make sure all the detail is right so that maybe we can look at something longer-term."

Folau's retention would be a boon for the ARU at a time when some of its biggest names are queuing up to leave Australia after the World Cup. Will Genia, James Horwill, Adam Ashley-Cooper, Wycliff Palu, Sekope Kepu and Scott Higginbotham have already announced their departures for Europe, while Reds playmaker Quade Cooper also looks increasingly likely to jump ship.

As little as a year ago, the deal being hatched to keep Folau in Australian rugby would not have been possible, with the ARU executive and board convinced its hard line on Test eligibility was the best way of defending the strength of the domestic game.

But in detail to be revealed within the next month, the ARU will make official its recent experiments in allowing a select group of players to play the coming season in Japan's Top League if they re-commit to Australian rugby in 2016.

Wallabies Ben McCalman and Bernard Foley are the only other players currently in the frame for short-term deals in Japan after this year's World Cup, while Force winger Nick Cummins is already enjoying the fruits of an early version of a flexible contract that is allowing him to play in Australia between seasons with Top League club Coca Cola Red Sparks.

Cheika said the inevitable competition for Folau's signature was a driving force behind the ARU's re-think.

"They have brought that in particularly for that reason, for a marquee player like this," he said.

Waratahs boss Greg Harris gave his qualified support to the ARU's call to stand firm on not selecting overseas-based players for Test matches.

ARU boss Bill Pulver has continued to resist calls to relax Test selection rules for players including Matt Giteau (France) and Kane Douglas (Ireland). Harris said the ARU had the picture "three-quarters right" but urged them to give Wallabies coaches a limited number of discretionary call-ups each year.

"I don't think you can have a carte blanche situation with that, but I think you can be strategic and if you've got a hole in your program somewhere and you can introduce somebody who's going to make a difference, then I think a coach needs to have that flexibility," Harris said.

Meanwhile, the Waratahs have named Test big guns Adam Ashley-Cooper and Tatafu Polota-Nau to make their returns via the bench against the Stormers at Allianz Stadium on Saturday.

Waratahs team: Israel Folau, Taqele Naiyarovoro, Matt Carraro, Kurtley Beale, Rob Horne, Bernard Foley, Nick Phipps, Wycliff Palu, Michael Hooper, Jacques Potgieter, Dave Dennis (c), Will Skelton, Sekope Kepu, Tolu Latu, Benn Robinson. Res (two to be omitted): Tatafu Polota-Nau, Jeremy Tilse, Paddy Ryan, Mitchell Chapman, Pat McCutcheon, Stephen Hoiles, Brendan McKibbin, Adam Ashley-Cooper, Peter Betham, Jono Lance.