NEYMAR PLAYED ON many big stages with Barcelona but rarely was he given his own. With Paris Saint-Germain, he gets his wish. His debut at Guingamp was broadcast in 183 countries, and it's that sort of pull, along with his standing in the game, which demonstrates why PSG owner Nasser Al-Khelaifi was happy to double the previous world record transfer fee and pay €222 million to sign him.

But it's ultimately on the biggest stage of them all -- the Champions League, the group stage of which kicks off this week -- where Neymar and Al-Khelaifi, who also agreed to spend €180m for the services of Kylian Mbappe, need to come up with the goods.

At 25, Neymar has years on the two stars he hopes his move to France will help dethrone: Cristiano Ronaldo (32) and Lionel Messi (30). He's already on the way, and, you indeed get the feeling from his frequent Instagram stories and social media profiles that as a brand, he's already the more natural, modern icon for millennial fans.

The Brazil forward was the only footballer listed in Time's most recent 100 Most Influential People. According to Forbes, even before his Paris relocation, he was the third highest-earning player on the planet behind Ronaldo and Messi and the only one of the three making more in endorsements than through his salary.

Online, Neymar has 80 million Instagram followers, 60 million likes on his Facebook page and 30 million Twitter followers. Moreover, his social media posts feel authentic and genuine, in contrast to those of Ronaldo (staged and, often, bizarre) and Messi (reluctant). It's this sort of marketability that saw Barca promote him extensively in Japan, the United States and China.

🙈🙊🙉🎵🎤 @dejesusoficial #TBT 😂🤣 A post shared by Nj 🇧🇷 👻 neymarjr (@neymarjr) on Aug 17, 2017 at 8:35am PDT

And he's not bad on the pitch, as PSG found out in March when he was the figurehead in Barca's 6-1 Champions League comeback win at Camp Nou. He's so good, in fact, that the debate has shifted from whether he's overrated to if he's disrespectfully good. Opposition sides kick and elbow him to stop him, his "provocative" style is criticised and his box of tricks and rainbow flicks are deemed distasteful.

But Neymar has not achieved what his former Santos coach Muricy Ramalho predicted he would by 2014: He has not become the best player in the world. Four years at Barca helped him get closer, but they did not take him over the line.

Neymar's move from Barcelona to PSG was the signing of the transfer window. EPA/CHRISTOPHE PETIT TESSON

MONEY IS OFTEN coupled with status and while Neymar's presentation buzz words in August were "project" and "challenge," cynics suggested "money" and "Ballon d'Or" might have been more applicable. However, as much as finances played a part in the transfer, so did the promise that, away from Messi, he can become the world's best.

It's what Neymar has been working so hard to achieve for so long. David Espina, who is Ronaldo Nazario's former communications director and has worked with other Barca Brazilians in the past, sees a determination to succeed in Neymar that he did not in Ronaldinho and Romario.

"While other Brazilians trained to maintain, Neymar has always trained to improve," Espina told ESPN FC earlier this year while Neymar was still at Barcelona. "Perhaps only Rivaldo had the same dedication."

That has meant plenty of work in his own time, as Eduardo Musa, who managed the player's image rights until the end of 2015, saw at first hand.

Each day after training, Neymar would be met at his Pedralbes home just outside Barcelona's city centre by Ricardo Rosa and Rafael Martini, respectively his personal fitness coach and his physiotherapist. Both have followed him to France.

The first thing they would do was take measurements: calves, quadriceps, shoulders and so on. Neymar weighed 64.5 kilograms when he arrived in Catalonia, since when Rosa and Martini have helped him edge towards 70 kilograms. No stone was left unturned and the progress was meticulously followed.

It was a delicate process because, as Musa explained to ESPN FC earlier this year, while Neymar was still at Barcelona, they had to ensure that the weight gain did not compromise Neymar's speed and agility, two fundamental parts of his game.

Rosa and Martini's other big challenge is injury prevention, and for that, they haven't worked alone: Neymar installed a pneumatic compressor unit -- effectively an anti-fatigue and muscle recovery machine -- in his home. All Barca players use them once to twice a week at the training ground, but Neymar was so enamoured with the technology that he wanted one to himself.

The results have been positive, but there's still room for improvement. He played more than 40 games in each of his four seasons at Barca, missing 86 days through injury in his first two and just 47 in his final two. In total, he averaged 46.5 games per season, slightly fewer than Messi (51) and Ronaldo (48.75) during the same period.

Brazilian chef Marcela Lermy, meanwhile, has helped streamline Neymar's diet. Messi's work with Giuliano Poser, an Italian doctor who specialises in kinesiology, saw him make wholesale changes to stay at the top of his game, such as ditching sugar, and Neymar has followed suit.

Not that it has been easy. As a teenager Neymar would eat junk food and drink soda. People tried and failed to change his patterns in Brazil, but in Barcelona he upped his nutrition game.

Lermy slowly weaned him off white sugar, first replacing it with brown sugar and honey and then gradually reducing the amount he consumed. Other changes have been simple but effective. Everything is now more natural -- fresh juices and salads -- and he eats much less meat, although he still has a soft spot for Brazilian dishes, with arroz e feijão (basically rice and beans) providing a taste of home.

In four seasons with Barcelona, Neymar scored 105 goals in 186 games. Charlie Crowhurst/Getty Images

DESPITE ALL THE steps Neymar has taken to push himself has far as possible and the success he has enjoyed on the pitch, the way he spends his little free time has brought criticism.

Whether taking in Copa America games with high-profile friends Justin Bieber and Jamie Foxx, a suspension that coincided with his sister's birthday celebrations in Brazil or spontaneously heading to London on a day off, where he would be spotted with members of One Direction, Neymar's private life has irked some.

And not just supporters; some at Barca felt his lifestyle showed a lack of dedication. After a training ground argument last season with Juan Carlos Unzue, Luis Enrique's assistant, it was reported Neymar's professionalism was the centre of the discussion. Messi, it's argued, doesn't come with the same baggage. By contrast, some like to suggest Neymar lacks the adherence to truly sustain himself as the world's best.

The Catalan press were often particularly tough on him; Diario Sport's Lluis Mascaro once referenced Neymar's "partying" by saying "his nights out are not suitable. As the proverb goes, Cesar's wife 'ought not even be under suspicion.'"

That, though, contradicts what Musa and Espina have seen.

"I don't think it's a problem," Musa says. "He likes training. If he gets a play in his head, until he's perfected it, he will work and work and work on it. So with training and with so many trips [for games and sponsors]... It's not a normal life, let's say.

"But I think he lives well. It's not easy. He can't just go to a bar with friends; it's not possible. If he says 'I want to eat here tonight,' it might not be possible. You have to work out how he goes in [the restaurant] and how he leaves because there's so much attention."

So Neymar would often prefer to stay home in Barcelona, playing computer games (Counter-Strike: Global Offensive on the desktop and parchis with friends on the iPad), teaching himself piano and surrounding himself with friends and family: Joclecio Amancio, a former footballer who he calls his brother, his father and his sister, mainly. His son, David Lucca (4), also moved to the city with his mum.

Anything else, according to Musa and Espina, is exaggerated. Neymar can still enjoy himself on a yacht in Saint Tropez surrounded by friends and become the best player in the world, they argue. The two aren't mutually exclusive.

After he starred alongside Lionel Messi at the Camp Nou, Neymar will be the star in Paris. Ira L. Black/Corbis via Getty Images

"ONE PERCENT CHANCE, 99 percent faith."

It was a phrase that looked like being a watershed moment for Neymar at Camp Nou. Instead, it may have been the beginning of the end.

It was something he had said before Barca's earth-shaking comeback against PSG in the Champions League in March and, the following day, a huge banner carrying the motto adorned the city's high-end shopping street Passeig de Gracia.

He was the immediate poster boy of the win, but time has left us with a photograph of Messi, with his fist punching the air in front of disbelieving supporters.

Neymar works with Nike, Gillette, Red Bull, GaGa, BEATZ, Replay, Police, Listerine and a number of other brands, but even his fusion of marketing and social media popularity couldn't elevate him above his teammate. Some Spanish reports claim this marked a moment of realisation, that he must leave in order to fulfill Ramalho's prophecy.

He had flirted with Paris before. Wagner Ribeiro, his former agent who still works with his dad, revealed the staggering terms which were laid on the table in 2016: A network of hotels around the world, a private jet and €40m annual salary, tax free.

The answer a year ago was no. Playing alongside Messi was still preferable, with an eventual passing of the baton appearing to remain inevitable.

But something changed. Perhaps the deterioration of his relationship with the Barca board had something to do with it, but ultimately, playing with his idol proved simply to be the next phase of his education, a finishing school from which he graduated with his move to Paris.

There, he can cast his own shadow if he leads PSG to their first ever Champions League title.