The Queensland Maroons have been hit by an enormous double coronavirus blow, with both Cameron Munster and Murray Taulagi set to miss the decider next Wednesday in Brisbane.

While Taulagi was only drafted into Queensland's starting side for Game 2 in Perth after Xavier Coates suffered an ankle injury during the series opener - won by the Maroons - in Sydney, Munster is one of Queensland's most important players.

The QRL released a statement confirming the two players have tested positive on RAT tests and are awaiting the results of PCR tests.

"Queensland Maroons players Cameron Munster and Murray Taulagi returned positive Rapid Antigen Tests today," the statement read.

"Both players have received PCR swabs to confirm whether they have COVID-19. They are isolating from the group while results from these swabs are pending.

"All other players have returned negative RAT tests.

"The Maroons are following all protocols as advised by the NRL."

The star Melbourne Storm five-eighth Munster has played 15 State of Origin games since debuting for the men from north of the Tweed in 2017, to go with his 164 NRL games.

His form this season has gone to a new level despite the ongoing contract speculation which surrounds him off-field, and he was at his best for the Maroons in Game 1, before battling through a shoulder injury to complete Game 2 in Perth as the Blues kept the series alive.

He had overcome that shoulder injury and was expected to line up for the Maroons on Wednesday night, with both Tom Dearden and Sydney Roosters' young gun Sam Walker in the squad on standby for rookie coach Billy Slater, who is now facing the biggest hurdle of his short coaching career.

Dearden - having served as 18th man for Game 1 and 2 - is now likely to come into the starting side to make his Origin debut alongside Daly Cherry-Evans in the halves.

Taulagi is a far easier replacement for the Maroons however, with Hamiso Tabuai-Fidow, who was in the squad for Game 1 but injured for Game 2, to be called straight into the starting side after he impressed during his Origin debut last year.

The QRL have also confirmed that Corey Oates has joined the squad.

The concern for Queensland will be whether the virus has travelled any further through the camp, with the QRL now needing to draft new standby players in to replace the two that move into the starting side.

It's anticipated the QRL will confirm the squad changes on Saturday ahead of Wednesday night's decider, to kick-off at 8:10pm (AEST) in Brisbane.