Rapana is likely to join Panasonic Wild Knights, the Japanese franchise coached by former Wallabies and Crusaders mentor Robbie Deans.

The Raiders are keen to retain Rapana, who is off contract at the end of the season. They have tabled the winger a new deal but, due to salary cap constraints, it is only a fraction of what he can earn from cashed-up overseas rugby clubs.

Rapana is keen to make the move, although he hasn't ruled out a return to the NRL following the stint abroad.

The 30-year-old made his NRL debut for the Gold Coast in 2008, but is no stranger to the 15-man code. After completing a Mormon mission, he signed with the Western Force in 2012 and played for the Palmyra Rugby Union Club in Western Australia. He shifted to Canberra the following season with a view to earning a contract with the ACT Brumbies, but was ultimately spotted and signed by the Raiders in 2014.

Since then, he has made his name as one of the most effective wingers in the NRL, forming a formidable combination with Joey Leilua, affectionately dubbed "Leipana". The 2017 Dally M winger of the year has battled shoulder, rib and knee injuries this year, but will be a key man for the Green Machine in their finals campaign.

An official announcement on Rapana's future may not come until Canberra's season comes to an end to ensure the focus remains solely on their premiership charge.

Canberra are keen to retain the nucleus of the side that has secured a top-four finish. Charnze Nicoll-Klokstad earned a significant pay rise with a new three-year deal after initially leaving the Warriors for a base annual salary of just $130,000.

Along with Parramatta's Maika Sivo, Nicoll-Klokstad has been the bargain buy of the season, cementing the fullback spot and scoring 17 tries in his first year in the nation's capital. Raiders officials are also in discussions with the management of English imports Ryan Sutton and Elliott Whitehead, who are contracted until the end of 2020.

Rival clubs will be able to approach them from November 1 and the club is hopeful of securing their services before then.

The English quartet of Sutton, Whitehead, Josh Hodgson and John Bateman has been key in Canberra's impressive rise up the ladder this season.

The signing of another Super League star, Wigan halfback George Williams on a three-year deal from 2020, has prompted speculation about the future of Aidan Sezer.

The half, who kicked three field goals in the dramatic win over Cronulla last weekend, has been linked to a move to English side Huddersfield despite having another year to run on his contract.

Canberra coach Ricky Stuart rested several influential players, including Nicoll-Klokstad, Rapana, Sia Soliola and Bateman, for Saturday's clash with the Warriors.