The only major trophy in football that neither Cristiano Ronaldo nor Lionel Messi have ever won is the World Cup.
Messi came closest when Argentina reached the final four years ago, only to lose to Germany in extra time.
In his three previous attempts, Ronaldo has never gone beyond the semi-final stage and a fourth-place finish in 2006 when Portugal were defeated 1-0 by France.
The Portuguese reached the last eight in 2010 in Germany, but could not get out of the group stage in Brazil four years ago.
At 33, this is probably Ronaldo’s last chance while he is a top player, though he recently claimed that he intends to play until he is 41.
Given his motivation for continually proving doubters wrong, it would be a brave person who ruled him out of lining up in 2026 at the tournament shared by the United States, Mexico and Canada.
That would mean a further two World Cups for the Real Madrid forward, but older players in a top league tend to quit international football long before club football.
Even with an in-form Ronaldo, Portugal, the European champions, are not considered one of the favourites to win the tournament.
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Being in a tough group with Spain, Morocco and an Iran team unbeaten in four years in competitive games is a factor, yet Portugal were similarly disregarded two years ago at the European Championships in France.
Portugal went on to win, albeit in a dour style, drawing matches, then snatching victories in extra time or on penalties.
They benefited from a favourable draw in the knockout rounds, inadvertently created by their mediocre form in the group stages, as a draw with Iceland left them third in Group F.
If they had topped the group, they would have faced in-form Belgium. Instead they got Croatia, then Poland.
They played Wales in the semi-final, before overcoming a France side cramped by their own fears in the final.
Performances have been unimpressive since that Paris final, but Portugal get results – they won nine of their 10 qualifying games under boss Fernando Santos. They also reached the semi-finals in the Confederations Cup a year ago.
Ronaldo remains the stand-out star and was a very interested observer of this week’s bombshell for Spain, Portugal’s first opponents on Friday in Sochi.
Departed Spain boss Julen Lopetegui will become his new boss at Real Madrid and internet memes pictured Ronaldo and Madrid's president Florentino Perez laughing as if they had colluded to upset Spain on the eve of the World Cup.
Ronaldo has issues of his own with Perez and was unwise to speak out on live television about his Madrid future minutes after the Champions League final victory against Liverpool two weeks ago.
As his teammates celebrated a third consecutive European Cup, Ronaldo hinted that his future might not be at the Bernabeu.
Even by his own self-centred standards of constantly posturing for improved contracts, it was too much, and he backed down the following day.
From his perspective, he is the best player on the planet and should be paid more than any other, but Portugal’s greatest ever player only ever looks avaricious and slighted.
Manchester United fans are tired of him allowing his people to link him to a return to Old Trafford – and the club are once bitten, twice shy.
Sir Alex Ferguson even told his players that Ronaldo was coming back to Manchester in 2013, but Ferguson departed and Ronaldo’s intentions are always doubtful.
Since making his debut in 2003, Ronaldo has played 150 times for his country, scoring 81 goals – a record unmatched by any player in Russia.
He scored 15 goals in qualifying games – another record unmatched by any player in Russia, but scoring four times against Andorra or a hat-trick against the Faroe Islands as Portugal’s captain did in qualifying is not where Ronaldo will be judged.
He remains a match-winner, and while Portugal, who can only draw from a country with 10 million inhabitants, don’t have the strength in depth of Spain, who can draw from five times as many, they do have other excellent players.
Goncalo Guedes, 21, who played up front alongside Ronaldo in their last friendly, a 3-0 win over Algeria, was magnificent for Valencia last season.
Fellow wide man Bernardo Silva, 23, is very highly rated by Manchester City. Veteran defenders Pepe, 35 and Bruno Alves, 36, play in front of the excellent Rui Patricio, but the focus will always be on Ronaldo.
He knows it, he is in good form and ready to win a first World Cup, but it remains the greatest ask of a stellar career.