The FA has today written to Manchester United Manager Sir Alex Ferguson and assistant coach Carlos Queiroz to ask them to explain their media comments made following Manchester United's FA Cup Sixth Round tie against Portsmouth.

Ferguson has been asked to explain his comments about referee Martin Atkinson and PGMO General Manager Keith Hackett.

Queiroz has been asked to explain his comments about referee Martin Atkinson.

Both parties have until Wednesday 19 March to respond.