Stuart fears Papalii could spend time on sidelines

Raiders coach Ricky Stuart will be sweating on scan results for a shoulder injury enforcer Josh Papalii suffered in Canberra's 18-6 loss to the Roosters on Saturday night.

Papalii lasted just 31 minutes after receiving a blow to his shoulder while taking a carry in the first half and failed to return once he left the field. The scans will be taken on Monday.

The injury robbed the game of a possible second-half dual with returning star Sonny Bill Williams as the Roosters kicked away in Papalii's absence for an 18-6 win.

"[I'm] concerned, yeah," Stuart said.

"We'll find out how serious it is. For Josh not to come back on, he's obviously feeling it.

"If Josh is out we'll find someone to fill the jumper. I said it six or seven weeks ago when everyone wrote us off.

"No one gave us the ability to show what's inside this playing group. The mentality.

"They have shown you how much spirit is in there."

Stuart was left disappointed with the side's second-half performance after pushing the Roosters in the opening period despite trailing 10-6.

A poor completion rate in the final 40 minutes killed off any momentum Stuart's men were building in a bid to level the scores. 

The side's best chance to strike back, when they forced an error with Williams' first touch, was quickly undone through a Siliva Havili mistake.

"We were two different teams," Stuart said.

"It disappoints me because it was a real quality game of football in the first half and we just lost our way.

"I've got to give them credit for how they hung in there because with the fundamental errors they made it's a wonder they didn't score another three tries.

"We'll look at it and move on."

The loss keeps the Raiders in fifth spot leading into clashes against the Dragons, Warriors and Sharks to finish the regular season. 

The Roosters, now two points clear of the Raiders in fourth on the ladder, face the Knights next week in a crucial clash that will affect both sides' chances of pushing for a top-four finish. 

"It didn't hinge just tonight on the top four, there is still some football to be played," Stuart said.

"[But] it was an important two points. More for me the way we played in the second half was more disappointing than losing the two points.

"We were really loose. It just wasn't us."