One vacancy in Queensland's State of Origin side is a certainty with Josh McGuire suffering a serious injury in Brisbane's 44-22 NRL thumping of Newcastle.
And another threatens for the Maroons after Broncos winger Darius Boyd came off late in Friday night's clash with a groin complaint.
NSW coach Laurie Daley also looks set for some anxious moments before July 8's Origin decider in Brisbane with Newcastle hitman Beau Scott (shoulder) leaving the field after 15 minutes not to return.
At the least, Queensland coach Mal Meninga will need to announce a rejigged interchange bench when he names his side on Monday after Maroons reserve forward McGuire (Achilles) went down in the 58th minute.
Canberra's Josh Papalii or Sydney Roosters enforcer Dylan Napa appear his most likely replacement.
And it remains to be seen whether Meninga will also have to tinker with his backline after Boyd failed to go the distance in Brisbane's fifth straight win.
Broncos coach Wayne Bennett said he felt for McGuire but played down concern over Boyd.
He said McGuire would in fact lean on Boyd and captain Justin Hodges who have both previously overcome Achilles injuries to bounce back to their best.
"He had just been rewarded with Origin selection and showed everyone how well he can play. But that's the game we play," Bennett said of McGuire.
Hodges tried to console the 25-year-old prop who came onto the field after fulltime on crutches.
"It's devastating for him. It's a big injury. But he works hard and takes no short cuts - he will be back," Hodges said.
Hodges admitted McGuire's injury was a bigger blow to ladder leaders Brisbane than Queensland.
Daley may also need to re-think his 17 after Scott left Suncorp Stadium early.
Knights coach Rick Stone said scans on Saturday may reveal the full extent of the injury.
A player who did push his Origin cause was Knights centre and Queensland prospect Dane Gagai who helped Newcastle fight back from a 20-0 deficit after 28 minutes.
Newcastle couldn't take a trick early with Scott joined on the sideline by lock Robbie Rochow (25th minute) and playmaker Jarrod Mullen (foot) failing a pre-match fitness test.
Newcastle - who led the competition after four rounds - have now won just one of their past 11 games and are on a five game losing run.
Not everything went right for Brisbane who also lost interchange back Dale Copley to a heavy head knock in the 58th minute.
The Knights launched a somewhat stunning counter-attack after being down four tries to nil and trailed by just four points when Korbin Sims crashed over in the 58th.
But there was no denying Brisbane, who piled on the next three tries to seal their sixth straight home game in front of 27,246 fans.
Second rower Matt Gillett and winger Lachlan Maranta nabbed doubles.