The Raiders fined Shillington an undisclosed amount on Friday for breaching the club's media policy, also concerned by his comments that Raiders players had been pushing for the appointment of sacked assistant Andrew Dunemann ahead of the newly appointed coach, Ricky Stuart.

Shillington quit the Raiders senior leadership group earlier this year in frustration at the leniency that had been shown over the years to Dugan and Ferguson, who have both been sacked from the NRL club this season.

On Thursday, Shillington told Fairfax Media: "Depending on how the coach handles you or how the club handles you, sometimes you create the devil in players.

''If a player mucks up and you don't drop him from the team or you don't have some sort of serious consequences ... I think that's when you create the devil in players.

"It makes them bigger than the club, and I think we saw that at our club this year with a few players."

Dugan, who infamously cost himself a multi-million contract at the Brisbane Broncos earlier this year for controversial comments on Twitter, could not refrain again on Friday.

The St George Illawarra Dragons fullback posted on Twitter: ''I think Shillington forgets he went DUI twice lol he's done some favours to get that Australian jersey. Well done mate.''

''Not saying I'm not lucky but he needs to move on and stop sledging me every chance he gets.''

Dugan's outburst was retweeted by both Ferguson and another former sacked Raiders player Todd Carney, before Dugan deleted them from his Twitter account.

Shillington was banned from driving for 12 months in 2010 after being convicted of his second drink-driving offence, when he registered a blood-alcohol reading of 0.115 – more than twice the legal limit. It was his second disqualified for drink driving.

Shillington would not comment when contacted by Fairfax Media about Dugan's tweets or the fine from the Raiders.

Shillington's comments on the Canberra coaching appointment could also have a flow-on effect to his relationship with Stuart.

Shillington had stated in Friday media that Stuart's hardline stance to discipline could be ''just what the doctor ordered''.

But it's understood Raiders officials were disturbed by Shillington's ongoing comments backing Dunemann, given it could be viewed as undermining the incoming coach.

There is already speculation Stuart and Shillington don't see eye-to-eye, dating back to when they were at the Sydney Roosters.

Raiders chief executive Don Furner said Shillington had breached the club's media policy.

''They should not comment on issues outside of their immediate responsibilities as a player without prior approval from senior management,'' Furner said in a statement.

"David is an experienced senior player at this club and should have known better.

''He has been spoken to previously about errant comments he has made to the media and the negative impact they can have.

"I have spoken to David today and he acknowledged that some of his comments were not appropriate and he was sorry."

Former Test halfback and now media commentator Greg Alexander said Shillington's comments would only cause ''he possibility of another fracture in the club''.

Alexander said Shillington was within his rights to talk about the appointment of Stuart and changing the culture within the Raiders.

However, he believed statements about senior players wanting Dunemann served no purpose other than to force a wedge between the players and Stuart.

''I don't mind his comments in regard to the culture, it's obvious the senior players weren't happy with some of the things,'' Alexander said.

''If I was the Canberra club I'd be asking him what he was trying to get across when he mentioned the Dunemann thing, he needs a wake-up for that.

''By him commenting on it, it's opened up a couple of wounds and gives the possibility of another fracture in the club.''

The 30-year-old Kangaroos and Queensland representative has had a mixed season.

He lost his place in the Maroons team after the opening game of the State of Origin series.

He made the media comments while in camp with the Prime Minister's XIII, where he hopes to regain a place in the Australian team for the World Cup.