Carrick was signed by Sir Alex for Manchester United from Tottenham.
He told The Times: "He was my boss for seven years at a crucial time in my career.
"I had coaches who trained, trained, trained - and you felt that you were trained, trained, trained. But the key is to help the players without realising it. He was a genius for just that."
And how Ferguson actually excelled in that discipline, Carrick tries to give an example.
"These were ways in which he behaved and how he treated you and how he set the tone.
"Only afterwards do you realise how much it shaped you. My first start was against Watford, not a fantastic match, but we won 2-1.
"If it had been in Tottenham, we would have thought, far result, well done, but he entered the dressing room and lost his mind: 'It wasn't good enough at all. Not Manchester United standards'. And I thought, 'F***, this is different'."
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