MANCHESTER, England -- Manchester United manager Sir Alex Ferguson was charged with improper conduct by the Football Association on Thursday.

Ferguson harshly criticized referee Martin Atkinson after United's 2-1 defeat to Chelsea on Tuesday. The United boss was upset that Atkinson didn't send off Chelsea defender David Luiz for a second yellow card following fouls on Javier Hernandez and Wayne Rooney and that Chelsea was later awarded a "soft" penalty kick.

Frank Lampard scored from the penalty spot in the 79th minute to give Chelsea a 2-1 victory. Luiz scored the Blues' first goal earlier in the second half as they rallied from a first-half deficit.

"You hope you get a really strong referee in games like this," Ferguson said. "It was a major game for both clubs and you want a fair referee, you know ... You want a strong referee, anyway, and we didn't get that."

Ferguson has until March 8 to appeal the charge.