"Messi is the best player in history", the coach once said in 2017.
The Portuguese manager just "has to" select his home nation and "knows what [he] wants" with their opponents.
He leaves the ultimate result to the viewers' imaginations. "He has extraordinary players and a coach which has given him a plus", he added.
It is a stretch to make Portugal one of the favourites to win the trophy, even with Ronaldo, but they are nevertheless in Russian Federation as the reigning European champions after surprising France on home soil two years ago. It's highly likely that once word gets round to him, he won't take it well.
The latter is one of four Portugal players - along with William Carvalho, Bruno Fernandes and Rui Patricio - who say they will be breaking their contracts with Ronaldo's first club, Sporting Lisbon, after being attacked by disgruntled fans last month.
Spain and Portugal will meet on Friday in the city of Sochi, where they will be the star of Group B of the Russian tournament, which kicks off on Thursday.
While both players are already considered bonafide all-time greats, neither has a World Cup winners' medal in his collection.
Many football fans still believe that in order to be recognised as the greatest footballer ever, you need to win a World Cup, just like Pele and Diego Maradona managed to do during their illustrious careers.
That experience, and inside knowledge of numerous Spain players, will be crucial on Friday by the Black Sea.