Canberra are bracing for Aidan Sezer's expected exit to the Super League by securing back-up half Sam Williams on a new two-year deal.

But plans for the Raiders to make their own English excursion in the pre-season have been put on ice due to a lengthy international calendar that won't see their Great Britain stars return to training until January.

Grand final halfback Sezer is tipped to seek a release from the final year of his Canberra contract to take up a three-year deal with Huddersfield.

English Test half George Williams will be the Green Machine's first-choice No.7 in 2020.

His namesake Sam however will remain at the club as well, NRL.com understanding that he has recently agreed to a new two-year deal, with a 2021 option in the club's favour.

While Sezer may be UK-bound, the Raiders have put a potential pre-season game against Wigan on the backburner.

The two clubs' growing relationship and a slew of English recruits had Canberra exploring a possible UK trip to start their 2020 campaign.

Raiders' top five tries of 2019

However the logistics around pre-season returns – Great Britain players Josh Hodgson, Elliott Whitehead, John Bateman and Williams won't report back to Raiders HQ until the New Year – have scotched plans for the trip this season.

The Raiders may still look to revive the idea next summer, but will then have a Kangaroos tour of the UK to work around.

Sam Williams's signature meanwhile is one of the last pieces of Canberra's roster puzzle to fall into place after Jordan Rapana's confirmed move to Japanese rugby and Joey Leilua's re-commitment for next year.

Salary cap restrictions may still leave Leilua with little option but to move on at the end of next season.

Canberra first granted the blockbusting centre permission to explore his options as their current plans will see them struggle to match his market value in any new deal beyond 2020.

But for now at least Leilua is staying put.

"I guarantee I'll be there next year," he told NRL.com last week.

"I've got one more year left so I'll see out my contract there and whatever happens after that is part of work.

"You've just got to move on or if I stay – I'd love to stay, but sometimes it doesn't work the way you want it to.

"We'll just see how it goes, we'll have to play it by ear and see what my family wants to do."

Canberra has also bumped up former Knights hooker Tom Starling and Jersey Flegg player of the year Harley Smith-Shields to full-time deals next year.