In the autumn of 2002, when some unwise people suggested Sir Alex Ferguson was over the hill, the great Hugh McIlvanney sounded a note of caution. “The most crazily virulent of his denouncers have been telling him he is lucky to be holding on to his job,” wrote McIlvanney in the Sunday Times. “Maybe they should make sure he is properly buried before devoting themselves too gleefully to dancing on his grave. He could be a pretty awkward revenant.”

That last phrase has regularly sprung to mind in recent weeks, and not only because of the omnipresent DVD of Leonardo DiCaprio’s Oscar-winning portrayal of a Brian Kilcline lookalike. The main reason is that Cristiano Ronaldo has become the awkward revenant of Euro 2016. In the group stages, when he absurdly denounced Iceland’s “small mentality” and missed a penalty against Austria, his critics did a lot more to his grave than just dance on it.

There was little wrong with questioning whether Ronaldo was past his best; when a sportsman reaches 30, it is human nature to look for signs that he has lost his nip. But the sneering, celebratory tone of much of the criticism, as well as lacking empathy, felt ill-advised. A lot of people could be foaming with impotent rage on Sunday. Schadenfreude can be a boomerang, especially when it involves sportsmen with the mental strength and relentlessness of Ronaldo. He has redefined WE Hickson’s old proverb: if at 42nd you don’t succeed, try, try, try again.

Ronaldo’s belief is perhaps his greatest quality. Yet even he must have wondered whether he would have another chance to win a major tournament with Portugal. At the age of 19 he played in the defeat to Greece in the final of Euro 2004, missing a decent late chance and breaking down in tears after the game. Since then there have been two semi-finals, in the 2006 World Cup and at Euro 2012, but Portugal’s miserable World Cup campaign two years ago suggested a team in decline. They came to this tournament with a 38-year-old geriatrico in defence and a strikerless, wingerless formation that looks like a mushroom and with about as much cutting edge most of the time. They have been dependent on moments of brilliance from Ronaldo, most notably against Wales and Hungary. And while he certainly hasn’t lorded over the tournament like Diego Maradona during Mexico 86, he has still scored three and made three.

Amusingly enough, Ronaldo’s chance of completing his CV by winning Euro 2016 is in no small part down to Iceland demonstrating more than a small mentality. When they were hanging on at 1-1 in their final group game, knowing a goal for Austria would put them out, they still had enough positive intent to counterattack and score a winner. That bumped Portugal down to third in the group and meant their run to the final was Croatia, Poland and Wales rather than England, France and Germany.

If Portugal win their first major trophy on Sunday, and particularly if Ronaldo plays a significant part, it will strengthen the argument that he, rather than Lionel Messi or Zinedine Zidane, is the greatest player since Maradona, and that he is the greatest European footballer of all time. It is true that international football does not ache with quite the same importance of old, but to many eyes it is still the ultimate. Mario Götze will never be a Pointless answer.

It is hard to overestimate what it would mean for Portugal to win their first international trophy (no, we’re not counting the Fifa World Cup Most Entertaining Team award for 2006, especially as they scored one goal in three knockout games). That they have been one of the less exciting teams to reach a European Championship final may bother the increasingly garrulous football snobs, but it probably won’t have much historical significance. If they win, Ronaldo’s medal will say “Uefa Euro 2016, France”, not “Uefa Euro 2016, France, where Portugal were a sedative and Ronaldo upset Iceland a bit”.

The timing of a victory would barely be sweeter, given Messi’s recent personal and professional problems. The debate over who is the best has become almost tediously emotive. The endless capacity for geeky discussions and lists of this nature, a happy place for post-Hornby men everywhere, is one of the billions of things that has been compromised by inescapable internet cranks whose disposition makes Livia Soprano seem happy-go-lucky by comparison. Sitting on the fence is becoming a virtue.

I’d be more comfortable putting Ronaldo above Messi than above the late Johan Cruyff, simply because they play in the same era. You can make a legitimate argument either way, but the case for Ronaldo is that he has outlasted Messi, who has been in relative decline since 2013; that he has overcome far greater adversity and ill-will; and that he has achieved as much despite playing in relatively inferior teams.

It is harder to compare Ronaldo and Messi to the all-time greats of the past. Cruyff, Maradona and Pelé played a different sport. The two main reasons – smooth pitches and the fact GBH is no longer punishable with only a yellow card – make it hard to know what contemporary achievements are worth in old money. Instinct suggests Maradona is the greatest because of what he did with Argentina and Napoli, but you would do well to create an unanswerable case.

We can say two things with reasonable certainty, however. The widespread dislike of Ronaldo means he does not always get the credit he deserves for his astonishing career; and if Portugal win Euro 2016 on Sunday, he is going to be one seriously awkward revenant.