The Manchester United boss is ready to face the Blancos at Old Trafford on Tuesday, and thinks that 'The Special One' could spring a surprise and remain in Spain
The Portuguese boss led los Blancos to the title last year, but they currently trail bitter rivals Barcelona by 13 points, and 'The Special One' is facing speculation over his long-term future, with a potential return to Chelsea on the cards.
Yet although many assume this will be the last season at the Bernabeu for Mourinho, the Red Devils boss - who will face his old adversary in the Champions League on Tuesday - doubts whether the 50-year-old will leave.
"You see all these things on Mourinho but he's got two years left on his contract," Ferguson told reporters. "Everyone assumes he'll leave but I heard that last year, too. I'm not certain he'll leave.
"Maybe it's possible because there's no smoke without fire and I'm sure that clubs would love to take him. He's given me no indication. I don't know how they can replace someone like him, anyway. I think he's done a great job there.
"A reasonable assessment of his time at Real Madrid has got to be countered with how good Barcelona have been. They've been an exceptional team.
"Would you really want to let a good coach like that go? I don't think [Real Madrid president Florentino] Perez would want that. So what you are reading about Chelsea and all the rest - I just think it would be difficult for Jose to leave Real Madrid because he's at the top."
While Sir Alex feels Mourinho could stay with Madrid, he admits a lot could rest on whether the Spanish giants progress past his own side in the Champions League on Tuesday evening.
"I wouldn't know how they'd react to going out," he continued. "They have that Spanish mentality and have changed their manager that many times over the years.
"For Jose and for Perez and the supporters, the European cup is going to be really important for them this season, there’s no doubt about that."