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 the club's website, 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.