Trent Robinson is optimistic Cooper Cronk will be fit to face his former club Melbourne Storm in the NRL Grand Final despite sustaining a shoulder injury in the derby victory over South Sydney Rabbitohs.

The inspirational Sydney Roosters half-back did the damage when he was tackled by Adam Reynolds attempting a field goal just before the break at ANZ Stadium in the Preliminary Final on Saturday. 

Cronk played through the pain barrier in the second half after being treated at the interval, putting his body on the line in a 12-4 win over the Roosters' arch-rivals.

Roosters head coach Robinson expects the playmaker to take his place in the side against the club where he spent 15 seasons before moving on last year.

"Obviously ice [will be applied], and he'll go and get scans," Robinson said. "I know you want information straight away and after the scans we'll know more.

"I'd say he'd be right to play next week though."

Robinson said there was never any prospect of Cronk being replaced at half-time.

"No, definitely not," he said. "It wasn't even discussed. To be honest, I didn't even ask how he was.

"Cooper knows how he is and he needed to get work done [on his shoulder] at half-time. He was always going to go back out there but it looked pretty sore."

Robinson also stated he has no concerns that co-captain Jake Friend could be banned for the showdown with the defending champions for a first-half tackle on Greg Inglis.

Tries from Daniel Tupou, Blake Ferguson and Paul Momirovski sealed the Roosters' place in the decider next Sunday.