The Football Association have charged Manchester United manager Sir Alex Ferguson with improper conduct on Thursday.Ferguson was quoted by club channel MUTV as stating he 'feared the worst' when he saw referee Martin Atkinson was to take charge for United's English Premier League clash with Chelsea at Stamford Bridge on Tuesday, before commenting that his side failed to get 'a fair referee or a strong referee anyway'.The comments were fuelled by Atkinson's decision not to send off Chelsea's David Luiz, despite the Brazilian seeming to trip United striker Wayne Rooney while on a yellow card.To rub salt in United's wounds, the central referee later gave captain Nemanja Vidic his marching orders in second-half injury time, ruling the centre-back out of his side's trip to Liverpool on Sunday.The 69-year-old Ferguson looks likely to face a two-game touchline ban when his case is heard next week, with the ban delayed given the FA regards such a case as 'non-standard'.The Scot's two-game ban is likely given he served two of a suspended four-match ban last season for comments regarding referee Alan Wiley's fitness.The delay in enforcing the punishment means Ferguson will be allowed in the technical area at Anfield.