Ferguson was discussing his team's temperament when he had a dig at Benitez.
He declared: "We know it is a hard job, it is hard at the start and it is hard at the end. I don't have any doubts about our temperament. I think there is enough experience in the same place.
"They always want to win, that is the mentality they have here. There will always be twists and turns, it happens.
"Two or three years ago Liverpool beat us 4-1 at Old Trafford and that genius Benitez said they had planned to beat us by playing long balls in behind.
"Remember that? Clown."