Broncos second-rower Matt Gillett was one of several players to back up from Origin II.

The Brisbane Broncos have suffered another huge injury blow heading into their Thursday night clash with the Sydney Roosters at Allianz Stadium. 

Second-row forward Matt Gillett has been ruled out after failing a fitness test on his injured shoulder at training on Wednesday morning. 

It means 19-year-old Jaydn Su'A will come into the starting side in what will be just his fourth NRL appearance. 

Gillett will join representative forwards Sam Thaiday and Josh McGuire on the sidelines, with both sitting out a week due to suspension. 

A concerned Wayne Bennett broke the news on Wednesday, with the master coach conceding his team is facing a tough task without all that experience. 

"Matt Gillett won't play so Jaydn Su'A will come into the starting team in his place," Bennett said. 

"Gillett is pretty close to returning, but he just wasn't right today so hopefully he will be fine by next week. It's not that we're being cautious, he's just not fit to play. 

"Jaydn is a really good young kid. He's only 19 and having a few weeks out has been really good for him. 

"He hasn't been up playing first grade every week so there's no doubt that he'll be fresh and ready to go. 

"It's a good learning curve for our young kids. It's all part of our future. We have four on our interchange bench that probably have no more than 20 games between them and that's part of the pain you have to take sometimes. 

"Hopefully in five years time they'll be the guys that will be leading the team and forming the forward pack."

 

 
Gillett's injury is the type of bad luck that Brisbane could ill afford heading into their important clash with the Roosters. 

A win on Thursday night is vital for the Broncos to stay in touch with the top four, with many thinking a loss to the Roosters would all but end their hopes of finishing at the top end of the competition. 

Gillett joins a growing injury list that includes international representatives Kodi Nikorima, Jack Reed and Jordan Kahu.

In the absence of those stars Bennett called for his young troops to make a statement when they run out onto the field on Thursday. 

"We need to get our attitude back on track," he said. 

"Our defence is fine; we just need to have more desire. 

"My challenge now is to get us back to the form that we had at the start of the season. 

"We are in a bit of a rough patch and we need to come back into our winning ways sooner rather than later."