This is supposed to be his last best chance.

Or maybe the best chance has already come and gone, squandered deep in extra time on a humid night in Rio de Janeiro almost four years ago.

We have an incorrigible habit of revising sports history, and of glorifying the past to the point where the present can never measure up. Which is why somehow, unfathomably, indefensibly, unconscionably, there isn’t yet a consensus that Lionel Messi is the greatest soccer player of all time.

Absolutely nobody has dominated the sport of soccer as completely as Messi has, and for as long as Messi has. He has transcended the game for a decade, floating above it all in the company of the only slightly more human Cristiano Ronaldo. He has won and scored and dazzled so often that any kind of comprehensive highlight tape of his career would turn into a 20-volume opus.

Still there are doubters and detractors. They prefer Pele, even though his first two of three World Cup titles came as a piece of perhaps the greatest national team of all time, and in spite of the Brazilian never playing his club soccer in the superior European leagues. Or they prop up Diego Maradona, ignoring the fact that his prime was brief, cannibalized by the Argentine’s insatiable appetite for drugs and parties.

But they both won the World Cup. Messi has never won the World Cup.

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That’s the only argument against him. On the face of it, judging any body of work by performance in a quadrennial tournament in which you’re hugely dependent on circumstance — conditions, draws, supporting cast, referees, luck — is stupid. It’s also stupid upon closer inspection.

This thesis asserts that if, in Brazil in 2014, Mario Goetze hadn’t chested down Andre Schurrle’s cross and volleyed it into the net — a shot of enormous difficulty — in the 113th minute, and Argentina had perhaps won the World Cup final against Germany on penalties, Messi’s legacy would be different. It holds, essentially, that Goetze’s volley, and the alternative outcomes it precluded, invalidate every other one of the millions of moments of Messi’s career and prevent him from being the greatest. Which he would otherwise be. So something largely out of his control, something he didn’t do, cancels out all that he’s done. Or something?

Right. Sure.

Never mind that Messi dragged Argentina into a World Cup final without anywhere near the kind of squad depth Germany boasted. That he, in fact, brought La Albiceleste to three straight major finals, with a pair of Copa Americas following the World Cup summer. All three title games were lost after regulation — both Copa America finals ended with Chile winning on penalty kicks.

Can Messi truly not be the greatest without winning a major tournament with Argentina? And if so, does that then make Ronaldo the greatest, after he led Portugal on a fluky run to the 2016 European championship? The logic doesn’t hold up, because Ronaldo had to be substituted after the 25th minute of the final due to injury.

If, however, the unanimous and universal cementing of Messi’s legacy really does depend on triumphing at a World Cup, he may not like his chances. Messi turns 31 during the tournament in Russia. He’ll be a few months past 35 at the 2022 edition in Qatar, since it will take place in the late fall. And he’s already briefly retired from the national team once, after the 2016 Copa final in New Jersey.

And this Argentina side probably isn’t as good as the one that made its run from 2014 through 2016. Qualifying for this World Cup was shambolic and looked all the more hopeless at one stage during Messi’s international retirement. Argentina only squeaked into tournament on the final matchday. Meanwhile, Germany has only gotten deeper while France and Brazil look like superpowers again — perhaps Belgium does too.

And the spine of a team that was at the peak of its powers now seems past it.

Javier Mascherano and Angel Di Maria have fallen off in the last few years. In the back, only Nicolas Otamendi and Marcos Rojo are bona fide World Cup-level defenders, but neither is famed for his reliability. Up front, Gonzalo Higuain is still known more for fluffing the most consequential of chances than scoring boatloads of goals. And Sergio Aguero — the third-highest scoring Argentine ever — has never entirely meshed with Messi. In goal, meanwhile, Argentina has only underwhelming options.

It doesn’t help that manager Jorge Sampaoli has refused to cycle in younger stars. Striker Mauro Icardi has scored at least 22 Serie A goals for Inter Milan in three of the last four seasons and could well reach 30 this year. He’s 25. Paulo Dybala is 24 and already one of the best attackers in the world, thriving at Juventus and constantly rumored to be headed to Barcelona to join up with Messi.

But Sampaoli left both off his roster during this international break. They likely won’t make the World Cup team either. The manager believes they don’t fit his system. And so the key players are all in their 30s, or close to it.

The expectation from Sampaoli is clear. It’s all up to Messi. “He is the best of all and is in a stage of maturity that can he can carry the team on his shoulders,” he said recently. “This is going to be his team.”

The manager has argued that soccer owes Messi a World Cup.

Maybe it does. But it doesn’t really matter. Messi has nothing left to prove. Winning a World Cup, or failing to, wouldn’t change that.

Leander Schaerlaeckens is a Yahoo Sports soccer columnist and a sports communication lecturer at Marist College. Follow him on Twitter @LeanderAlphabet.