Dragons captain Cameron McInnes is set to miss the start of the season after scans revealed he suffered a medium-to-high grade MCL injury at the NRL Nines.
There was better news for St George Illawarra impact forward Korbin Sims - who was feared to have rebroken the same arm he hurt last year - as tests showed no new fractures.
Meanwhile, Roosters skipper Boyd Cordner has been rested from his side's World Club Challenge match against St Helens in England on Sunday morning (AEDT), while the Warriors have lost prop Bunty Afoa to a ruptured ACL which could see him miss the entire 2020 season.
McInnes, 25, injured his knee during his club's Nines grand final defeat to the Cowboys at Perth's HBF Park last weekend.
The inspirational hooker, who was named captain in January, is expected to be sidelined for between six to 12 weeks.
Veteran dummy-half recruit Issac Luke looks likely to wear the No.9 in his place, having initially been tipped for a bench role.
"The specifics of [McInnes's return to play] timeframe will be determined by how quickly the ligament tightens up. That'll be assessed later this week," St George Illawarra head of athletic performance Nathan Pickworth told dragons.com.au.
Cameron McInnes in focus
Dragons fullback Matt Dufty had surgery on Monday night to stabilise his fractured cheekbone and will spend around four weeks out.
The timeframe gives the speedster some hope of being available for the round one clash against Wests Tigers at WIN Stadium on March 15, though Zac Lomax is all but locked in to start at fullback.
No specific recovery period was given for Sims.
"Korbs seems to have dodged a bullet. His X-ray and CT [scans] have shown no new fractures," Pickworth said.
"He's still quite sore so we've got a follow-up MRI scan today [Tuesday] and a meeting with the specialist this afternoon. Once we've gone through those investigations, we can determine the exact course of action and when he'll be back on the park."
Having endured a heavy workload at club, state and international level over the past few seasons, the Roosters decided it was best to rest Cordner.
"Long-term we think this is the best way to go. It's really hard to miss a game like the World Club Challenge but it’s been a big few years," Cordner told News Corp.
"We're looking at the bigger picture. I'll be fresh mentally and physically for round one."