It is a hammer blow for Queensland. Munster was their best player in Game 1 and has always stepped up with heroic performances when it matters in the Origin arena.
The QRL released a statement on Friday night.
"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. Corey Oates will join the Maroons squad tonight."
Speaking on Nine News, Darren Lockyer said it may not be fatal but it was a huge blow for the Maroons.
"I still think they can (win), huge news I'm just hearing myself," Lockyer said.
"I'm just trying to think who replaces Cameron Munster if he can't play, I think probably Tom Dearden who has been in camp for the past two games would be the likely replacement there."
The Maroons also have Roosters half Sam Walker in camp as an option.
Nine News QLD's Luike Bradnam wrote: "Turns out Covid is a NSW supporter. Anyone but Munster," and: "To put this context for you NSW supporters as to how devastating the Munster news is for us QLDs this would be like you hearing Ashley Klein is out of the decider."
Moreton MP Graham Perrett tweeted: "Congratulations New South Wales. It was a wonderful series."
On Fox League, Maroons great Cooper Cronk called it a "curveball".
"That's a huge rock to Billy Slater's team," Cronk added.
"(Munster) was great in game one, arguably in the form of his career, to have him not available — yet to be confirmed — and Murray Taulagi to make his second appearance at Origin level too."
Cronk said Dearden, Walker and Hunt were all options.
New Zealand great Benji Marshall said the test "changes the game" due to Munster's effect on his club team Melbourne, who has lost four of seven games during the Origin period.
"I think he's the X-factor guy, I think he brings a lot of energy, and to me, his performances have been the best for Queensland," Marshall said.
"I think he's a massive loss. I know they do have a guy like Ben Hunt and guys like Tom Dearden and that. But I think the make up of the side they had had what it takes to beat NSW in this game. Without Munster, I think it puts a bit of doubt in it."
