Brisbane Broncos captain Adam Reynolds has admitted he could feel his injury throughout the NRL grand final.

Fears for a torn groin or hip injury were raised during the first half when Reynolds went down awkwardly in a tackle.

It came as the Broncos struggled to find any headway against a Penrith side who, despite having all the ball and territory, couldn't put points on the board.

But when Reynolds went down and was immediately assessed by medical staff, fears of the game becoming a blowout were immediate.

They weren't realised however as Reynolds played through the pain barrier to stay on the park and guide his side to a 24-8 lead, only to see it evaporate as Nathan Cleary put on one of the all-time great performances in steering the now three-time premiers back from the brink.

Reynolds admitted he was sore and felt it throughout the game.

"I was a little sore. I was tossing up whether to give the kicking duties over to Walshy [Reece Walsh]," he said during the post-game press conference.

"I could feel it throughout the game but it wasn't bad enough to stop me from doing things."

Despite the injury, Reynolds only appeared to be hampered for a handful of minutes before steering Brisbane around the park with relative ease of movement, although his kicking game at times seemed off during the second half.

The Broncos went on to lose the game 26-24.