AAP

Instead of feeling relief over Paul Gallen's withdrawal, Queensland are fearful of the man they expect will replace him in the Blues starting pack - Andrew Fifita.

The Maroons had every right to breath a little easier after NSW skipper Gallen finally succumbed to a foot injury ahead of Wednesday night's State of Origin decider in Sydney.

However, Queensland back-rower Sam Thaiday looked like a worried man on Sunday as he contemplated what the 196cm, 114kg Fifita might produce if asked to fill Gallen's shoes.

"He's been one of their best forwards in both games. We know he is going to be a handful," he said on Sunday.

"And with Paul Gallen out, they are going to look at blokes like him, (James) Tamou and Boyd Cordner to share his load.

"I am sure they are up to the challenge, especially Fifita."

Fifita is in such blockbusting form that he is rated the NRL's best forward, even though he starts off the Cronulla bench.

He gave yet another taste of what he can do with a typically blockbusting display, capped by two tries in his last NRL game for the Sharks, a 36-22 win over former club Wests Tigers.

Thaiday did not sound surprised by Fifita's rise after rubbing shoulders with the Sharks giant in this year's Indigenous All Stars side.

"I think he has come of age this year. I think it started at that Indigenous All Stars game," he said.

"He has always been a player who was going to do something if he really wanted to.

"The way he has been playing, I am sure he will get a World Cup spot at the end of the year."

Fellow Queensland back-rower Chris McQueen said Fifita's presence would ensure the Maroons could not drop their guard despite Gallen's loss.

"He is another workhorse just like Gallen," he said.

"He's big and strong, runs hard every time he has the ball.

"If he gets that starting spot, he is going to make an impact.

"They (NSW) have had a pretty disrupted preparation but, come Wednesday night, none of that is going to matter - they are going to bring it."