Raiders fullback Charnze Nicoll-Klokstad celebrates a try.

Canberra coach Ricky Stuart is preparing his side for a North Queensland ambush this weekend in the wake of the Cowboys' second-half collapse in round three.

The Cowboys were quickly out of the contest last weekend against Cronulla after having five tries scored against them in the 20 minutes after half-time.

However, Stuart expected the Cowboys to show a strengthened resolve in the middle third of the field as they strive to not drop to 1-3.

"They'll be a lot better this week, it's probably not the time to get them in regards to their last outing," Stuart said of North Queensland.

"I know (Cowboys coach) Paul Green will have them very much turned around and have a different mindset so it's going to be a tough game, but we always have tough games up there."

Canberra is likely to err on the side of caution with its two injured stars ahead of the trip to Townsville with Joe Tapine and Aidan Sezer despite the pair being rated as "close" to playing by Stuart.

"They're both going to be close, I'll speak to the medical team, [Tuesday] but if I had to put money on it right now I don't think Aidan will be okay," Stuart said.

"Joey Tapine is probably closer than Aidan.

"I won't play either of the boys if they aren't well and truly 100 per cent fit.

"Taps wasn't fit last game and he hurt his thumb early, so it shows we're better off resting somebody rather than aggravating an injury."

Sam Williams played an important role for the Raiders in their win over Newcastle last weekend, scoring a try, having another denied and kicking the field goal to seal the victory on top of guiding the side around in greasy conditions in the second half.

Stuart said Williams' early season performance gives the club more options at the selection table.

"I was really happy for Sam because he had a good contribution to the game," he said.

"It's been difficult for him because he didn't know if he was going to be playing half or competing with Aidan, so when he got his opportunity he really aimed up."

Joey Leilua is free to play this weekend after entering an early guilty plea for his dangerous contact charge against Knights forward Tim Glasby.

Leilua has shown improved decision making and application to his defence this season, making 88 per cent of his tackles to date.

Stuart said Leilua knows there is a line between aggression and ill-discipline after the Glasby incident.

"I want him to keep that aggression, he's an intimidating big thing out there on that edge," Stuart said.

"There was a reason he did hit out at Glasby, but you just can’t do that. You have to put that reason to bed there in that moment.

"But I've spoken to BJ about it and he was remorseful, he doesn't like doing that type of stuff but he's maturing in a way that type of (incident) is becoming less frequent."