Cooper Cronk played grand final with broken shoulder blade

Cooper Cronk has put in a performance that Roosters skipper Boyd Cordner says will "go down in history" after it was revealed the halfback played the grand final with a fractured scapula.

Mystery had surrounded the nature of Cronk's injury all week, with most believing it was an issue with his rotator cuff. Minutes after the commanding 21-6 victory over the Storm, Cordner said Cronk had in fact broken his shoulder blade and was functioning at only 30 per cent.

Storied episode: Cooper Cronk and Boyd Cordner embrace after the halfback's amazing feat of playing injured.Credit: AAP

Cronk didn't run the ball once but managed to make nine tackles and not miss any, one of which was a hugely brave effort on his own line against Storm giant Nelson Asofa-Solomona.

Even Cronk's teammates couldn't believe his bravery, which will now go into the grand final annals alongside John Sattler's jaw and Sam Burgess's cheekbone in terms of sheer toughness.

"We knew Coops was touch-and-go there but he pulled through. It was touch-and-go all the way up until game time. We had to make up a game plan where we protected him as much as possible," Cordner said.

"Just him being there, him at 30 per cent. I think it will come out a bit later but he actually broke his scapula so that's a big performance by Coops. That will go down in history that's for sure."

A similar injury to Josh Reynolds saw him miss five weeks of the season. Cronk managed to power through a grand final in a role that was almost managerial but meant a huge amount to his Roosters teammates. He was hired to win a premiership and that's exactly what he did.

Such was his importance that Cordner admitted the Roosters had to devise a game plan based on 12 functioning players in attack, not 13. Luke Keary stepped up admirably to plug any gaps and earned himself a Clive Churchill Medal in the process.

"Not many would have seen what Coops did behind the scenes. He's a true champion and he played through a lot of pain," said Roosters hooker Jake Friend.

"For him to do what he did during the week and turn up and do what he had to do, he's a big part of why we're here and we love him."

Retiring champion Billy Slater had a special moment with Cronk after the game. Deflated in defeat, Slater said Cronk deserved all of the plaudits that come his way.

"He's a really good mate of mine, one of my best mates. It was really tough to see him play the second half that he did last week, knowing he was in doubt for this game. They hid that really well from us but what a courageous effort," Slater said.

"I told him how proud I was for him. I'm proud of the performance he put in... he was too good for us."

Slater was philosophical as he ended his wondrous career. Boos rained down as his voice was broadcast over the stadium speakers but he said the Roosters were just too big, too fast and too good.

"It's not how we planned. That's footy. They were better than us in the first half and they got out to a big lead. We just couldn't pull them back in," Slater said.

"We didn't help ourselves, we dropped a bit of the ball but the Roosters were just too good. We couldn't handle their big guys at the start. That's just the way it went."