The FA are contemplating whether to use a lip reader to investigate Jose Mourinho's touchline comments, according to Sky Sports.
Cameras caught Mourinho making comments following Saturday's dramatic 3-2 win over Newcastle United. It has been reported that some of those comments were swear words in Portuguese.
If the FA finds him guilty of using 'offensive, insulting or abusive language', Mourinho could receive a touchline ban for United's next match away at Chelsea.