Who will Argentina turn to without Lionel Messi?

When Lionel Scaloni took over as caretaker Argentina coach after the last World Cup, he was obsessed with France, the team who had just won the competition -- eliminating Argentina on the way. The future, said Scaloni, lay in quick transitions, in rapid counter-attacks. It was the style Argentina needed, and the style he was going to implant.

It lasted precisely one competitive game, a disastrous 2-0 defeat to Colombia in the 2019 Copa America.

There was an obvious flaw in Scaloni's argument. His idea of play was a very poor fit with his outstanding player. Scaloni was sufficiently shrewd, and sufficiently humble, to realise his error. During the rest of the tournament he rowed back, and started constructing a side that was better suited to the extraordinary talents of Lionel Messi.

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Match by match Argentina improved during the course of that Copa, when they lost to Brazil in the semifinals and ended up finishing third. They have not been beaten since. And Messi has seldom, if ever, looked happier representing his country. In place of Scaloni's original focus on the quick counter-attack, Argentina's game revolves around a possession-based midfield. Tottenham Hotspur's Giovani Lo Celso, in particular, has built a fine on-field relationship with Messi, who also dovetails well with Rodrigo De Paul and anchorman Leandro Parades. And his partnership with centre-forward Lautaro Martinez is getting better and better.

As Messi became disillusioned with Barcelona and is still new at Paris Saint-Germain, it appears that playing for Argentina has become even more important to him. The county's footballing public have certainly sensed this, and have built up an identification with him that is probably stronger than it has ever been, especially after beating Brazil in the Copa America final back in July.

Messi and Argentina can build towards next year's World Cup with a swagger of confidence, and he is enjoying himself so much that he is reluctant to call time on his international career. He said recently that Qatar 2022 will not necessarily be the end. He is taking it game by game.

But -- and this is a sad truth that football fans are going to have to get used to -- one day Messi will play his last game. At the age of 34, his final appearance is in sight. We will all have to get by without him. Argentina will have to get by without him.

It is possible that Friday's match away to Uruguay will offer a sneak preview into this unthinkable future. Messi is not 100% fit, with both knee and muscular problems. PSG are far from happy that he travelled across the Atlantic -- they think he should have stayed in Europe, working on his fitness.

Messi has been training but there must surely be a temptation to let him rest up and keep him fresh for Tuesday's home game against Brazil. It is probably not a temptation that Messi will feel as he is notorious for wanting to play all the time. But if Scaloni does leave him out of the Uruguay game, how can Argentina fill the void?

In the previous qualification campaign, for Russia 2018, Messi missed a number of games through injury and suspension, and Argentina struggled desperately without him. He had to perform heroics in the home straight to ensure that the team booked their place. This time, he has been ever present. Scaloni has not had to do without him in a competitive match. If Messi does not play on Friday, then the Uruguay game -- against highly motivated, dangerous opponents -- turns into a fascinating peak into the future.

What might Scaloni do?

Perhaps the nearest, easiest replacement would be Paulo Dybala. The Juventus striker has yet to make an impact in what so far has been an extremely disappointing international career. One of the problems, as Dybala has confessed in the past, has been the difficulty of clicking with Messi. Often both of them would be looking to receive the ball in the same space, and there is only one winner in that contest. Dybala has cut a diminished, intimidated figure. Perhaps he is now sufficiently mature to take advantage of Messi's possible absence.

Another choice with obvious virtues would be that of Joaquin Correa, often used by Scaloni as a second-half substitute. Correa has frequently come on to fill the centre-forward position, for which he is not a natural. Now he could line up alongside the real centre-forward, his Internazionale teammate Martinez.

And there is a third possibility, one being pushed strongly by the Argentine press -- River Plate's Julian Alvarez.

There is some hometown bias in this. With all the stars based in Europe, there is always delight to see home-based players get the call. This can reach ludicrous, even infantile levels of nationalism. Before the last World Cup, for example, some in the local media pushed the idea of the national team being composed of Messi, Cristian Pavon and nine others, and Boca Juniors winger Pavon was nowhere near good enough to receive such hype.

Is it different with Alvarez? The 21-year-old striker certainly has the potential to be a star. Quick, skillful, intelligent and versatile, he can play all across the attacking line and, in addition to his individual talent, he is a natural collaborator, using swift passes to unlock opposing defences. It is surprising that Alvarez is still based in Argentina, but River Plate coach Marcelo Gallardo has made a point of bringing him along gently, constructing a career for the long-term rather than looking for the short-term sale.

Has he been making a name for himself in a comfort zone, or might he be the type of player good enough to step into Messi's boots without it being embarrassing? These are questions that stretch well beyond the game against Uruguay. But Friday night in Montevideo might furnish some intriguing evidence.