Leilua went to see a specialist in Sydney on Thursday, with the Raiders expecting to know whether he needs surgery on a bulging disk on Friday.

If surgery isn't required then he could be back sooner.

A similar injury ended legend Andrew Johns' career, but South Sydney centre Kyle Turner came back after surgery in 2015.

Leilua suffered the injury during Canberra's loss to Manly at Brookvale two weeks ago.

It ruled him out of the Green Machine's win over the Penrith Panthers in Wagga Wagga on Saturday.

That was meant to be his 200^th NRL game, but he woke up with a sore neck on game day and was a late scratching.

The Raiders initially thought he would return for their crucial Magic Round clash against the Sydney Roosters at Suncorp Stadium on Sunday.

But now his 2019 season could be over.

It's a massive blow for the Green Machine after the 27-year-old had a sensational start to the campaign.

He's added some defensive starch to his renowned lethal attack, with his tackle efficiency of 86 per cent the best it's been since his stunning 2016 campaign.

Leilua's the Raiders' equal-leading try scorer with four, is equal leader for line breaks (five), and in their top three for tackle breaks (35) and offloads (11).

MORE RAIDERS NEWS

With Brisbane dropping incumbent NSW centre James Roberts for Friday night's clash with Manly, Leilua was in the mix to come into Brad Fittler's Blues team for this year's Origin series.

Stuart said bad luck was the one thing you didn't want.

"There's talk that it could be three months," he said.

"It could be longer. It could be good news around the corner and it's a little bit less.

"Until I know exactly from my medical team exactly where it's at it's hard to speculate."

Stuart admitted it was a big loss as they prepare for their top-four clash against the ladder-leading Roosters.

The Raiders are on the rise after an impressive start to the year, but a spate of injuries threatens to derail them.

On top of Leilua, they have Joe Tapine (ankle) and John Bateman (eye socket), who will return to England to visit family and friends following surgery.

But the plus side is it gives veteran Michael Oldfield a chance for an extended run in the team.

Oldfield has waited patiently since arriving in Canberra, playing just 10 NRL games in two years.

The most he's played is five consecutive games, but he's still scored eight tries in lime green.

He has the crucial task of marking up on Roosters star Latrell Mitchell.

"It will give Michael Oldfield a chance to cement a spot," Stuart said.

"It comes back down to individual's contributions now and that determines whether you get picked again in NRL or not."

It's looking likely that Jordan Rapana (ribs) will play, but Stuart said he still had to get through Thursday's training and then the captain's run on Saturday.

He's missed just one game since he was injured in the Manly loss.

But his fabled healing powers could see him back from injury twice before he was meant to return from last year's shoulder reconstruction.

Stuart was relieved they decided against using the salary cap relief to bring in a replacement because he would have been forced to sit out until round 13.

"I'll know more over the next couple of days," he said.

"I'm just so happy we didn't use his money at the start of the year in regards to the compensation we had because he could've played round one we were just taking a precautionary decision.

"So if I had've used his money he'd still be sitting out now. Fortunately we didn't ... I'm confident he'll get the OK to play."

NRL ROUND NINE

Sunday: Canberra Raiders v Sydney Roosters at Suncorp Stadium, 2pm.

Raiders squad: 1. Charnze Nicoll-Klokstad, 2. Nick Cotric, 3. Jarrod Croker (c), 4. Michael Oldfield, 5. Jordan Rapana, 6. Jack Wighton, 7. Sam Williams, 8. Josh Papalii, 9. Josh Hodgson (c), 10. Dunamis Lui, 11. Hudson Young, 12. Elliott Whitehead, 13. Ryan Sutton. Interchange: 14. Siliva Havili, 15. Bailey Simonsson, 16. Sia Soliola, 17. Corey Horsburgh. Reserves: 18. Aidan Sezer, 19. Emre Guler, 20. Royce Hunt, 21. Jack Murchie.

Roosters squad: 1. James Tedesco, 2. Daniel Tupou, 3. Latrell Mitchell, 4. Joseph Manu, 5. Matt Ikuvalu, 6. Luke Keary, 7. Cooper Cronk, 8. Jared Waerea-Hargreaves, 9. Victor Radley, 10. Siosiua Taukeiaho, 11. Boyd Cordner (c), 12. Angus Crichton, 13. Isaac Liu. Interchange: 14. Nat Butcher, 15. Zane Tetevano, 16. Sitili Tupouniua, 17. Mitchell Aubusson. Reserves: 18. Lindsay Collins, 19. Josh Curran, 20. Lachlan Lam, 21. Sam Verrills.