Queens Park Rangers manager Neil Warnock described Armand Traore as "an absolute disgrace" after his dismissal in Sunday's 1-1 draw with Aston Villa.
The left-back was shown a late second yellow card for a lunge at Marc Albrighton, though QPR recovered to snatch an equaliser in injury time.
"I just thought he was a disgrace," said Warnock. "I will fine him as much as I possibly can.
"I told him to his face 'you've let me down and you've let the team down'."
Traore dived into the challenge in an attempt to regain possession with QPR chasing the game, but Warnock was less than happy with his summer signing's actions.
The QPR boss added: "As an opposition player when you are winning 1-0 away from home, that is what you want. I just think he was a bit thick and naive.
"I said to him 'when we're playing at Fulham next week what are you going to be doing?' But he is learning. He is a good player and will be an even better one after that."
Traore's dismissal in the 90th minute came as QPR were still trailing 1-0, with Villa desperately defending their lead.
The hosts scored their leveller three minutes later, though, when Richard Dunne inadvertently skewed into his own net from a Heidar Helguson cross.
That cancelled out the visitors' controversial opener, a Barry Bannan spot-kick given for a shirt pull on Gabriel Agbonlahor by Traore.
It was a decision that prompted more choice words from Warnock, who was also unhappy that referee Michael Oliver opted not to award QPR a spot-kick when Alan Hutton appeared to handle on two occasions.
"Referees should be seen and not heard but he made it all about him," he said.
"It's disappointing to be talking about referees... there was nothing to referee in that game.
"Their's was never a penalty - I've never seen anything like that. Not one Villa player or fan appealed. Armand has blown on him. If you give that then you have to give 30 or 40 more fouls in a game. [But] he wants to give the penalty and it's wrong."
And on QPR's penalty appeals, he added: "The first one [Hutton handball] is embarrassing.
"How can that not be given as a penalty? He [the referee] can't even say he's in a bad position. My boys deserve better than that.
"As for the second, we're told that if you raise your hands it's a handball. He's raised his hands against Tommy Smith's cross."
Villa manager Alex McLeish, however, had a different view of things. Of his side's penalty award, he commented: "I was surprised nobody complained. Not a lot of Villa hands went up [but] I thought Gabby was impeded."
The draw extended Villa's unbeaten start to the season to six matches, but this was their fifth draw, something McLeish is keen to remedy in the coming weeks.
"I had to tell my players a few home truths at half-time because in the first half we were poor, very poor," said the Scot. "I let them know that in no uncertain terms and sure enough we came out a lot better in the second half.
"We should have been better in the final stages, though, and these are the opportunities we're missing. We'll work hard on the players and try to get them to the standards we want them to be at."