Keary: I'll step up to run show if Cronk's out

Roosters five-eighth Luke Keary says he won't give a second thought to what might or might not happen if halfback Cooper Cronk cannot play in Sunday's Telstra Premiership grand final against Melbourne due to injury but is confident he is up to the task if he needs to lead the team around if needed.

Keary starred for the Tricolours in their 12-4 preliminary final win  over the Rabbitohs at Allianz Stadium on Saturday night, taking control of the team when a shoulder injury reduced Cronk to basically an on-field coach in attack with the former Storm premiership-winner barely able to pass or kick.

If Cronk is ruled out Keary could play in the No.7 alongside someone like Ryan Matterson, or keep the five-eighth role but alongside a rookie half such as Sean O'Sullivan.

Either way it would heap plenty of extra responsibility on his shoulders but he has already shown he is up to the task.

"Obviously Coops had a shoulder injury so I just had to do a little bit more. We've prepared for it," Keary said after the win at Allianz Stadium.

"I knew what I had to do obviously. We were in front so I had to game manage, it would have been tough if we were behind.

"I just kind of had to game manage and get some kicks away for him and try and drive the boys into a position to get good kicks away, basically that was it. We couldn't really run too many plays without him so kind of did what we had to do in the end."

Keary finished with 361 kick metres against the Bunnies – a personal season high . His next most was 209 metres which came in round 18 against the Titans – the one game Cronk has missed this season and the one in which O'Sullivan made his debut at halfback.

"Over four or five years now of playing, I feel confident in myself that I can do that on these occasions," he added.