Concern is growing for Greg Inglis after Queensland medical staff ordered blood tests for the virus-hit Maroons centre.

What was first described as tonsillitis has become a chest infection that simply won’t go away in a major headache for the Maroons ahead of Wednesday night’s State of Origin opener in Sydney.

Maroons players and staff had been adamant all week that Inglis would play Origin I but changed their tune after Inglis underwent blood tests on Friday night.

“I think the doc has to make sure every box is ticked but it is looking a little more serious than we think,” Queensland forward Nate Myles said.

Inglis has been quarantined and on antibiotics since going down with the virus earlier in the week.

After Inglis savoured a team rest day on Saturday, Queensland have just one more training session before they fly out for Sydney on Sunday afternoon.

It remains to be seen whether Maroons officials make a final call on Inglis after Sunday’s training session at their Gold Coast camp.

Newcastle’s Dane Gagai has been called into the camp and is on standby while Maroons back Will Chambers said he was ready to fill Inglis’ shoes if needed despite having played just one Origin game to date – on the wing.

“If I have to, I’ll play there. We’ll just have to see what happens,” Chambers said on Saturday.

“GI is a pretty special player and he’ll do everything right to be there.

“We’ll see how it all goes.”

The news is better for two other veterans, fullback Billy Slater (shoulder) and centre Justin Hodges (foot).

Slater cruised through an opposed session on Friday night but did not take part in defensive drills afterwards as a precaution.

Hodges has received three stitches for a foot wound suffered in a bizarre bike crash at their Gold Coast camp but is set to return to training on Sunday.

Myles said the Queensland team had taken plenty away from the opposed session against the Burleigh Bears, especially with Slater back on board.

“Although there wasn’t much contact and wrestle to it (opposed session), I thought our shape and support and execution was pretty good,” Myles said.

“(Queensland coach) Mal (Meninga) wanted to make sure our start was good – it is so important this year.

“We missed the start last year (in a 12-8 loss to NSW in 2014 in Origin I) so we have to make sure we get it right.”