(Reuters) - Argentina's Lionel Messi, the most unassuming and also one of the most admired talents in world sport, can join the elite of soccer greats by winning the World Cup in Sunday's final against Germany.

There are two categories of truly great players - those like Pele and Maradona, who won the ultimate prize, and others such as Johan Cruyff, Eusebio and Ferenc Puskas whose brilliance was never in doubt but who had to be content with club prizes and individual accolades.

There are endless debates about who was the best but those discussions among fans do not in the slightest bother Messi - who never tires of pointing out that he plays a team game and that the glory belongs to the squad and not him alone.

That may sound like a standard cliched response, but it carries more weight from a player who does nothing to suggest he is anything but humble and more than a little shy.

While many other top players in the modern game seem eager to draw attention to themselves - with eye-catching goal celebrations and celebrity lifestyles, Messi is a reluctant superstar.

The 27-year-old does not seem to relish the work he has to do as part of his many endorsement deals and he keeps media appearances to a minimum.

When he does talk about himself he is evidently uncomfortable with discussions about his status in the game or comparisons with other players, past or present.

"Because the only thing that matters is playing," he said in a recent television interview. "I have enjoyed it since I was a little boy and I still try to do that every time I go on the pitch.

"I always say that when I no longer enjoy it or it's no longer fun to play, then I won't do it anymore. I do it because I love it," he said.

What Messi did not love was the view held by some Argentines that because he grew up in Spain, as part of Barcelona's academy system from the age of 11, he was not as committed to the national team as he should have been.

DOUBTS FADE

Those doubts over his desire to succeed with Argentina have faded in recent years, as any trip to Buenos Aries - where Messi's image adorns shop windows and billboards across the city - would prove, but it was a mood that upset the forward.

"It hurt, it bothered me. Because they said things that weren't true - that I didn't care as much about wearing the (Argentina) shirt. I didn't feel that, I didn't think that," he said in a 2012 interview with Time magazine.

"And now, I think what people there understand is that this is a team game, and that I try to play the same way there (for Argentina) as I do in Barcelona, and always do the best I can".

The roars from the travelling Argentine support in Brazil that have greeted the pre-game announcement of Messi's name are proof of that change but nothing would bring a better conclusion to that debate than winning Argentina their third world title.

Messi has four goals to his name in this tournament, despite being closely marked by opponents who have had months to prepare a strategy to stop him.

Against the Netherlands he again was forced to drift deep in search of space and possession but it is instructive to watch his eye movements even in those midfield roles.

Messi constantly glances towards the defense, building up a mental picture of what he will face when he turns to start one of those pacy, jinking runs that have led to so many goals for Barcelona.

That perhaps explains, partly at least, why Messi can suddenly turn a game even when he may look to have been marked out of it.

"Leo can make you win a match even on those days when he's in a low key, when his shining aura isn't there," says midfielder Javier Mascherano.

If there is a trophy in his hand on Sunday at the Maracana, modest Messi might even allow himself to share the limelight.