Paul McGregor remains convinced Tariq Sims should not have been charged by the NRL match review committee, describing his one-game suspension as a "hard pill to swallow".
Sims was found guilty of a dangerous contact charge against North Queensland's Michael Morgan, forcing him out of the NSW side for next Wednesday's Origin series decider in Sydney.
McGregor believes the Dragons did the right thing by challenging the initial grade two charge.
"I don't feel it was the right decision. I feel strongly about that," the St George Illawarra coach said.
"[The judiciary panel] obviously didn't think [the tackle] was as heavy as they initially charged, but they obviously found enough in it to warrant missing a game.
"I'm disappointed for Tariq. To miss an important game like Origin is a hard pill to swallow."
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The Dragons were optimistic about their prospects heading into Tuesday night's hearing.
"We went in there with a real good purpose that we thought he was not guilty," McGregor said.
"We challenged the decision, the decision was downgraded so he misses a round of footy.
"That's the decision and we've gotta wear that decision, but I still feel strongly that we did the right thing because we thought he was innocent.
"Our legal advice was to challenge it and Tariq wanted to challenge it because he couldn't go into a meeting and sit opposite three ex-players and talk about a thing he didn't do.
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"He really wanted to go in there with an honest approach of how he intended to tackle and that's what he did."
McGregor and Cowboys coach Paul Green drew extra attention to themselves after last Saturday's match in Wollongong with their post-game war of words.
McGregor effectively reaffirmed his stance when the subject was raised on Wednesday.
"I don't feel it's a coach's right to comment on an opposition player in that situation," he said.
"When it's spoken about in the post-match press conference it's highlighted to the public and obviously to the match review committee to do something about it.
"It's a coach having his player's back, but they've got a match review committee to watch the games and indicate if there's a follow-up process of any illegal action during the game."
The Dragons will be without Sims and four Origin players when they host Melbourne on Thursday night in Wollongong.
"I'm quite confident," McGregor said.
"We're playing at home and it's a good opportunity for the players to put it on the line.
"We're up against a very good football team so we're going to have to do a lot of things right, but [the lesser established first graders] have been waiting for this opportunity.
"I've got a good balance of experience and youth to match Melbourne's forward pack."