Jose Mourinho believes Portugal should not be discounted as potential World Cup challengers because the presence of Cristiano Ronaldo ensures "nothing is impossible".
Ronaldo was a key figure and captain as Portugal won Euro 2016, a victory which in itself was a shock given their perceived lack of star quality aside from the Real Madrid forward.
The European champions head into the World Cup ranked fourth in FIFA's rankings, though few consider them to be among the favourites, with Germany, Spain, France and Brazil the most widely fancied.
But Manchester United's Portuguese coach thinks both his country - who face Spain, Iran and Morocco in the group stage - and Argentina should be considered as in with a chance, purely because they have Ronaldo and Lionel Messi.
"Portugal has an interesting squad," Mourinho told ESPN. "Without Cristiano, it would be impossible, but with him nothing is impossible.
10 - Cristiano Ronaldo is the first player in Champions League history to score in 10 consecutive games (15 goals). Amazing. April 3, 2018
"I believe that the Argentinian national team without Lionel Messi wouldn't be a contender, but with him, they are one of the favourites.
"I like very much the basic structure of Brazil, their tactical [approach] and mentality. There is a mixture between natural Brazilian talent and a serious approach, physically, tactically.
"It is a team capable of defending well, allowing few goals, with a good support base. And then up front with Willian, Neymar, [Philippe] Coutinho and [Gabriel] Jesus – they are all players with outstanding qualities.
"And then we have the traditional teams of Europe, but I believe Spain is once again a real team. They were able to get together players with the same game philosophy, adapted to that playing style.
"I would say that Spain is in better condition than any other European rivals. But let's see. It's going to be entertaining to me, I'll be in Russia for a week to follow the games and then finally vacation."
