Hunt, who has already spent two matches on the sidelines with a hamstring strain, was selected to return against the Raiders but O'Brien said the powerful winger "pulled up sore" after Thursday's training session and was ruled out as a precaution.

"We're not willing to risk him," O'Brien said.

That means To'a will be recalled for his 15^th NRL game, lining up outside Tuala on Newcastle's right flank.

The pair have been exposed defensively in Newcastle's losses to Penrith (24-6) and Sydney Roosters (38-4) but O'Brien is expecting an improved performance against Canberra.

"We obviously spoke about that in our review [of the Roosters game]," O'Brien said. "We highlighted a couple of deficiencies there, and they've trained really well, so I'm confident. The good part about it is that you roll out the same guys, they get a chance to rectify things."

Hunt joins Mitchell Pearce (pectoral), Blake Green (ribs) and Edrick Lee (foot) on the injured list, but O'Brien looks set to welcome back Lachlan Fitzgibbon, who returned in NSW Cup last week after off-season shoulder surgery.

Fitzgibbon was named 18^th man on the official team sheet but O'Brien said he would be "comfortable" with promoting him, possibly to the starting line-up.

"I'm going to use this session now to confirm that," he said before his team's captain's run on Friday. "Everything else is confirmed. I was quite happy with Fitz last week, with his input into the NSW Cup game, so all things going well and he trains well, he'll definitely be in calculations."

Newcastle and Canberra have each lost five of their past six matches, and while they are still level on points with eighth-placed Gold Coast, O'Brien agreed his team have reached a crossroads in their season.

"Not necessarily in terms of ladder position, because we're two points out of the eight, so some other teams have done us some favours there," he said.

"But when your DNA, or your desire, or your hunger is being questioned, then there needs to be a response.

"That's not necessarily scoreboard or result. But there definitely needs to be some form of response. If we get that, you can be a little bit more confident for the rest of the season, that we can get back to the team I know we're capable of. But if you don't, well that's when you see some real headaches."

O'Brien is backing Phoenix Crossland, playing in his ninth NRL game, to handle the role of primary playmaker in the absence of Pearce and Green.

"The thing I do like about Phoenix is his physical contact," he said. "He's quite aggressive in that area, and he's got a good kicking game.

"It's a really simple game plan for Phoenix ... [but] we need 17 guys to contribute."