Raiders acting captain Elliott Whitehead says time is running out for them to get back to winning ways - ideally that starts against Newcastle at Wagga Wagga on Saturday.

Canberra have lost four in a row and slipped out of the top eight, but come up against a Knights side that's also struggling - having lost the past two games and sitting below the Raiders on the table on points differential.

Whitehead felt they made "mild improvement" in the loss to South Sydney, where they were denied two late tries that could have sent the game into golden point.

But he felt errors and "stupid" penalties hurt them.

"If we can cut them out then we'll be there or there abouts to getting back to winning ways," Whitehead said.

"We can't leave it too much longer. We have to get back to winning ways and hopefully that's next week against Newcastle.

"The boys can take a few positives out of that game - Souths are up there in the competition at the moment and I thought we pushed them.

"At times I thought we had the better of them. Hopefully we can get back to playing 80 minutes and not having little patches here and there."

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Whitehead has added another string to his Mr Fix It bow, captaining the side in Josh Hodgson (calf) and Jarrod Croker's absence (shoulder).

That was on top of a late switch into the halves to partner Jack Wighton after halfback George Williams suffered a slight hamstring strain in the warm-up.

It's hoped Williams could be fit to face the Knights, but if not Whitehead was confident they could cover the English international's absence.

Not only could Whitehead remain at five-eighth - with the chance of actually training there this week - but he said Sam Williams and Matt Frawley were also options.

Whitehead felt he still needed to work on his communication as a leader - although he didn't struggle for words when chatting outside the change rooms with NRL referee Ben Cummins about the controversial obstruction calls that ruled out two Raiders tries.

He felt lead-runner Emre Guler had gone through the Rabbitohs defensive line, but he said he wasn't a referee and it was their job to make the calls.

"I'm enjoying it. It's something different for me. I have to step up and talk more than I usually do," Whitehead said.

"At times I still struggle, but I've got a good group of boys around me that help me out as well.

"Jack, Josh and Jarrod, they all still talk in the change room beforehand so they make my job a little bit easier."

NRL ROUND NINE

Saturday: Canberra Raiders v Newcastle Knights at Wagga Wagga, 3pm.