Canberra captain Jarrod Croker said the ongoing NRL investigation around Jack Wighton won't be a distraction as the Raiders look to break their losing streak when they host Canterbury on Thursday night.

The NRL integrity unit is examining Wighton for allegedly being involved in an incident at a Canberra nightclub during the pre-season.

Croker backed Wighton to continue his sold form to start the year as the club tries to avoid its worst start to a season since 1982.  

"Jack's fine, he's in a good head space and he's right to play tomorrow tonight and he's got a little bub just about due as well," Croker said.

"Nothing has sort of happened at the moment and until we find out of our hands and until we find out the details and what happens we can go from there, but at the moment we're just focused on tomorrow night.

"If it does come to that (him being stood down) then we'll deal with it then."

If the Raiders were to lose Wighton for any length of time it would be another blow to their tough start to the season, with the 25-year-old one of their best players last week in their road loss to Manly.

Canberra's horror start to the season claimed another big name this week, with Queensland and Kangaroos forward Josh Papalii dropped to the Intrust Super Premiership by coach Ricky Stuart.

NRL Teams - Round 5

Croker hoped the tough stand proved nobody's place in the side was safe if they underperformed.

"It's disappointing it's come to that after four rounds, but we talk about making decisions for the team and putting the team first and unfortunately for Josh, that's the way it is this week," Croker said.

"It was the same for Blake (Austin) last week and both of those guys have handled it really well.

"They've just got to rip in this week, go back to Mounties and play their best footy and get back in the side.

"And for the boys playing in their position tomorrow night, it's a big chance for them to put their best foot forward and keep the jersey."

The poor discipline and attitude exuded by the Raiders has come under the microscope even more so this week as they face an equally desperate Bulldogs outfit.

A microcosm of the Raiders' issues in the first month came in the 60th minute against the Sea Eagles when Joey Leilua gave away a penalty for slapping the ball out of a Manly player's hands while getting back onside before a 20-metre restart.

The score at the time was 28-16 and the Raiders were never able to recover.

"We keep coming back to the word attitude and it's got to be 1000 times better tomorrow night," Croker said.

"There were probably signs of frustration coming out towards the back end of the game (last weekend), but we've knocked that on the head, none of that is acceptable and it doesn't help your cause.

"It (Leilua's penalty) was a silly little error and a brain snap and it's not going to happen again."