In an exclusive column in the Sun, the Portuguese manager was detailing his predictions for the Euro 2020 and naming some key players to keep an eye on.
Mourinho states that Ruben Dias is one of these players.
Talking of Portugal's chances of retaining their crown, Mourinho said, "Ruben Dias is the best centre back in the world now. With his move to the Premier League with Man City, he is getting a different level of knowledge. He is a fantastic centre back."
Such high praise hasn't come without some magnificent performances.
Ruben Dias has recently won both the Premier League and Football Writers Player of the Season, with the prestigious PFA award set to be announced on Sunday and the defender being one of the firm favourites for the title.
The Portuguese defender has had a transformational effect on both the Manchester City defence and the rest of his teammates ahead of him on the field.
Forming a formidable partnership with John Stones, Ruben Dias was a vital part of the clubs Premier League title win - especially the record breaking 21 consecutive wins in all competitions.
Joining last summer from Benfica, Dias came into the club with big pressure and a big price tag of around £61 million. His monumental impact has meant people have drew comparisons between the 24 year-old and the clubs greatest ever captain, Vincent Kompany.
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