Barry Robson has insisted Aberdeen had every right to appeal the red card shown to Graeme Shinnie as he blasted the four-game ban served to the midfielder.
Captain Shinnie had been shown a red card after a VAR review in the 1-0 win over Ross County after a challenge on Jack Baldwin.
Aberdeen appealed the decision but saw Shinnie hit with an extra match added to his suspension by the Scottish FA.
“As a club we have always done things very well when we have appealed different scenarios," said Robson when quizzed on the appeal fallout.
“We believed we were doing the right thing as we all looked at it closely and carefully.
“I am disappointed with the outcome, obviously.
“I think we had every right to appeal the decision.
“We are in dialogue that is ongoing. We can appeal it so the club are speaking about that.
“I am disappointed but we need to move on to the huge game at the weekend now and crack on for that."
Aberdeen remain in dialogue with the Scottish FA over the ban - raised from three to four after the unsuccessful appeal - with the hope a new review will take place.
Asked if he remains hopeful of a reverse on the decision, Robson added: "We hope so. We are clear on that, we really do.
“We have honest people at the club and when we have went down a route with players with any appeals we have always been honest.
“We have always tried to do our best.
“We know the type of player Graeme is so we are frustrated.
“The club will be dealing with that.
“We will not have Graeme at the weekend so it is an opportunity for someone else."
One player who could slot into Shinnie's position in the coming weeks could be youngster Connor Barron who is back in training after an injury layoff.
Despite his ban, Shinnie has remained in training with the Aberdeen squad as normal and Robson was quick to defend the Pittodrie player over his dismissal.
He said: “He’s okay. Graeme is fine as he is an experienced player and understands it.
“He is frustrated as you could all imagine, like the rest of us.
“Graeme is a top player and an honest player.
“Everybody in the Scottish game knows he is an honest player and he has never, to my knowledge, been sent off for a really bad challenge or anything like that.
“It is different if it is a player who that happens with regularly. But that has never happened with Graeme. He is training as normal.”
Aberdeen are headed towards a sell-out for the Sunday late afternoon clash against Rangers and the hosts head into the match in top form.
Robson's men have won six games on the bounce but the Aberdeen boss knows it'll take a complete performance to take anything this weekend having run Rangers close on occasion this season.
"It is always a good game against Rangers, obviously the fans enjoy it," said Robson.
"We know how good a side they are under Michael Beale and the way he likes to play, and you can see the team are getting stronger and stronger as the season goes on when I have watched them.
"His teams are always well coached and well drilled and they have some really good football players.
"It is going to be a difficult game for us but one we want to go and impose ourselves on.
"We are on a good run. It’s going to be a difficult game, but the message is clear to the players.
"We are at home, we want to try to impose ourselves on the game.
"We are going to have a full house behind us. We can’t think we have some divine right to win the game.
"We need to be and eight, nine or a 10 all over the pitch. If we do that we can give ourselves every chance of grabbing a result."