Star playmaker Johnathan Thurston had to be carried from the field during last night's shock loss 16 - 26 to the Tigers, and will be going for scans this week.
Preliminary observations suggest it was a calf problem, but looking at the worst-case scenario, it could be an achilles issue.
Coach Paul Green wouldn't feed into speculation, insisting that he'd wait to see the outcome of the scans.
"I'm not exactly sure. I don't want to speculate," Green said reports couriermail.com.au.
“I think it’s a calf at this stage. We’ll see how bad it is.
“We’ve been well below the average (of injuries) for probably three years. Eventually you’re going to go back to the average.
“This is our tough period.”
Looking ahead to Origin, the Maroons have already ruled out Matt Scott and Greg Inglis after serious injuries.
Thurston has a spectacular record for the most consecutive Origin appearances (36), and this series was set to be his last