The assistant referee who elbowed Andy Robertson is facing the risk of being sacked according to a former referees' chief.
Constantine Hatzidakis raised his elbow to the Liverpool defender's throat as the teams left the field at half-time during Sunday's thrilling 2-2 draw with Arsenal at Anfield.
He has been taken off duty while the Football Association investigate the incident.
Keith Hackett, formerly head of PGMOL, says the linesman on the day shouldn't have reacted the way he did and that his job could come under questioning.
He told BBC Radio Five Live: 'Ultimately, if he is found guilty of this, his career is in jeopardy.