The Anfield legend claims Benitez must end Liverpool's slump before their season completely falls apart.
"I will never advocate the sacking of any manager because I was someone who never had the bottle to do the job, but Benitez is under pressure," said Hansen.
"If you lose six games out of seven as Liverpool manager, you are under pressure. You cannot hide from it. If Liverpool's season is finished at the start of November, FA Cup apart, do not try and tell me Benitez is not under pressure.
"It makes the Champions League game against Lyon tomorrow and home league games against Birmingham and, particularly, Manchester City of huge significance now."