QUEENSLAND maestro Johnathan Thurston has given a positive assessment of his injured shoulder amid fears he may not regain fitness for next month’s State of Origin decider.

But the star North Queensland playmaker remains in serious doubt for his 300th NRL match against Penrith this Saturday.

Thurston produced one of the all-time great Origin performances in game two on Wednesday night, playing through the pain of a busted shoulder to break NSW’s hearts with a clutch sideline conversion, sealing a famous two-point win.

The Cowboys champion said immediately after the game in Sydney he had not suffered structural damage, rather a cork which had resulted in swelling. He would be assessed by club physio Steve Sartori before making a decision on whether he will take on Penrith in Townsville on the weekend.

Thurston was able to reaffirm his outlook upon waking up on Thursday.

“It’s a little bit tender, but it’s a lot better than I thought it would be,” he told reporters outside the Maroons’ hotel.

“It’s heaps better than when I first did it. I couldn’t lift my arm above my head.

“I’ve got a good range (of movement), so that’s a positive sign.”

Johnathan Thurston outside the Maroons’ hotel on Thursday. Picture: Peter Wallis

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The Cowboys match shapes as a massive event for Thurston as well as the North Queensland region. If he doesn’t take the field this week, he will rack up his 300th game in Canberra the following weekend.

And while he would prefer to celebrate in front of his friends, family and community, he said he wasn’t feeling any pressure to take the field knowing if he does there could be a danger of him missing the July 12 Origin decider at Suncorp Stadium.

“I’ll reassess when I get back (to Townsville) and talk to my medical staff there. If they give me the go-ahead, it should be fine,” he said. “It’s too early to call (for game three). We’ll just wait and see.

“Like I said, I trust the medical staff we’ve got. They know my body better than anyone. If they give me the green light, then I’m ready to roll.”

Playing in just his third game in 73 days, Thurston spent a large chunk of the match with his right arm dangling by his side.

He has played just once for his club since injuring his shoulder in the May 5 Test against New Zealand and came into the match under an injury cloud. He was tested out by Blues back-rower Tyson Frizell, who made a beeline from the centre of the field and ran at him all night.

After the match the 34-year-old had an ice pack strapped to his right shoulder but insisted he was no different to any other player who was playing through injury at this time of year.

Johnathan Thurston celebrates his clutch conversion. Picture. Phil Hillyard

Skipper Cameron Smith marvelled at his teammates’ resilience saying he was sometimes amazed at his ability to take the field.

“He’s got nearly every joint in his body strapped up tight,” Smith said. “He’s a warrior isn’t he? Some of the things he’s gone through in his career and still to be able to play at this level is incredible.

“He took a couple of whacks at training this week. I don’t know how he’s still able to get up for these matches sometimes.

“His body is not 100 per cent, there’s no doubt about that. He finds a way to get up for these games and make things happen.”