He said in an interview with AS: "I saw, I don't know where, that in his second year Mourinho has won a title with every team he has been with.
"I personally look at him, I see that self-assurance that he has in himself and I say: 'We are going to win something, yes'.
"We are going to have to win something. With that mentality, things get done."
The Spain international has long been an admirer of Mourinho and was touched by a gesture the Portuguese manager made at Christmas.
"I've always said that I wanted to play at some time in my life in the Premier and I had also said that I wanted Mourinho to coach me in my career. Many factors came together to make this possible," he said.
"Mourinho called me several times before making the decision. It was a reason to take into account, his insistence, because if he loved me so much it would be for something.
"I always say the same thing, I would like you to know him the way I know him. I could tell a thousand wonderful anecdotes.
"For example, on Christmas day, he knows that I am alone. We got to training on the 25th and I had a box at my space. I open it and it was a suckling pig already cooked.
"He told me: 'I know you are alone at Christmas, so you don't have to cook dinner and can eat well'. There are details that people don't know on a day-to-day basis. For a footballer, [the coach] being aware of how you are away from football is very important."
Alongside Spain coach Luis Enrique, Mourinho is one of the best managers the full-back has played for, while Madrid coach Zinedine Zidane was a notable exception from his top two.
"For me, Mourinho and Luis Enrique are two top coaches. Each one has his method, each teacher has his booklet," he said.
"Luis Enrique likes more to be in control of the ball, more like the Spanish philosophy of taking care of the ball. Mourinho likes that we are strong, that we also have the ball, of course, but they are different ways of training. But in their measure they are both top."
El lateral del Tottenham atiende a AS desde Londres. "No me sorprendió que Zidane no hablara conmigo", dice sobre su salida del Real Madrid.
'Sergio Reguilon on return to Madrid: "I don't know. Whenever I am asked about Real Madrid I say that it's a club which gave me everything, it's always been my home. Returning one day? That doesn't depend on me… I'm focused on the present, but it would be nice to go back in the future.'
Seems as if his goal is to do well in order for Real to buy him back, stay if he doesn't.
Not sure if this is a win win, or a lose lose for us. If he does too well, we lose him, if he doesn't perform, we keep him.
I guess we're going to have to hope he performs so well, just not as well as Mendy...
But it should put all the arguments akin to 'Why would he leave?' to rest - he clearly wants to return.