Mourinho, 48, has been heavily criticised in recent months for his outbursts on the sidelines and in front of the media, with the Portuguese most recently lambasted for raking the eye of Barcelona assistant Tito Vilanova at the end of last month's Spanish Supercopa defeat to the Catalans.
A number of people have spoken out against Mourinho, with former Real Madrid director Jorge Valdano insisting "no-one is proud" of his action and two-time European Cup-winning coach Ottmar Hitzfeld slamming his "boorish" attitude and "shameful" tactics.
But Ferguson, who Mourinho has been tipped to succeed in the Old Trafford hotseat, believes that the former Chelsea boss does not intend to be malicious.
"I don't find anything wrong with his enthusiasm,'' Ferguson told Corriere dello Sport. "When I was younger I showed more enthusiasm on the bench too. I was always gesticulating and directing.
"It's Mourinho's nature to be agitated. When I saw Mourinho run up and down the touchline at Old Trafford when he coached Porto, I said to myself, 'Did I also use to do that?'
"People recognise his enthusiasm. The fans understand that he's fighting for them and for the squad.''