Aston Villa have formally appealed against Zat Knight's red card in yesterday's Premier League match at Chelsea.
The centre-half was sent off after referee Phil Dowd awarded a penalty against him for a foul on Chelsea midfielder Michael Ballack during the 4-4 draw at Stamford Bridge yesterday.
"Villa have officially appealed against Zat Knight's debatable red card at Chelsea yesterday," said a statement on www.avfc.co.uk.
"Martin O'Neill was incensed by the decision and after reviewing the incident again this morning has decided to lodge a formal appeal in the hope that Knight can avoid a ban."
Knight is currently facing a one-match suspension for his dismissal at Stamford Bridge.
Ballack has denied diving to win the crucial penalty. Villa boss O'Neill suggested Ballack had tumbled over even though there had been no contact with Knight. Andriy Shevchenko rifled home the penalty to initiate Chelsea's fightback in a remarkable afternoon.
O'Neill felt Knight's dismissal in the 46th minute was the turning point and was furious with referee Dowd's decision.
But Ballack told the London Evening Standard: "For me there is no discussion about this. I had the ball and two guys, not just one, came and one pushed me. It was a clear penalty."
O'Neill declared after the match he might appeal Knight's red card after claiming Ballack had conned the referee.
He said: "It wasn't a penalty. The Chelsea player went over and there had been no contact."
Meanwhile, Chelsea defender Ashley Cole has also appealed against the red card he received in the match for handball on the goalline.