Can Mourinho restore Real Madrid to former glory?

That may be the biggest question Mourinho has to answer, with the Real dressing room containing Kylian Mbappe, Vinicius Jr and Jude Bellingham among a collection of elite players.

Mourinho's methods have traditionally relied on establishing strong relationships with key personalities and demanding total commitment.

"I think Bellingham will absolutely love Jose," said Huth. "He will thrive under him."

But he has concerns about Mbappe and Vinicius as he added: "When things don't go their way, things come out in the Press. I don't like that kind of thing.

"Bellingham is that kind of guy that gives everything each game. Jose loves that."

Managing such stars will prove a defining challenge for Mourinho, said Calderon too.

"The dressing room is full of stars, he has a fantastic squad," he added. "But it can be a problem if you don't manage it properly."

In his first managerial role at Porto, Mourinho was desperate to prove himself at the highest level and show his worth.

He took over midway through the 2001-02 season, famously saying he would make them champions the following year.

He delivered, building a team with relatively unknown players but hungry for success. He won the Portuguese title and Uefa Cup in 2003, then retained the league title and won the Champions League in the following season.

Journalist Monteiro admitted that version of Mourinho was impossible to recreate.

"What Mourinho did at Porto was a once-in-a-lifetime job," he said. "The big difference is that back then he needed to prove something.

"Now I think he only needs to prove something to himself - and sometimes that's not good for him."

At 63, Mourinho has nothing left to prove in terms of reputation, but Real Madrid may demand and need something different.

It's not simply the charisma and tactical intelligence that made him a global managerial icon, but the ability to adapt.

Huth said Mourinho still possessed "unbelievable knowledge" of the game, but now needed to convince the current players at Real Madrid to believe in him completely as those at Porto, Chelsea and Inter Milan once did in their quest for more honours.