The Football Association have contacted Manchester United manager Sir Alex Ferguson and assistant Carlos Queiroz to ask them to explain their comments following the FA Cup quarter-final defeat to Portsmouth.

An irate Ferguson claimed referee Martin Atkinson´s display was "unacceptable" and also accused referees´ chief Keith Hackett of "not doing his job properly" in the wake of Saturday´s 1-0 defeat at Old Trafford.

Ferguson and Queiroz, who also criticised Atkinson, were unhappy United were not given a first-half penalty for a challenge on Cristiano Ronaldo.

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