Chelsea's Oscar: The making of a boy wonder

When Oscar dos Santos Emboaba Junior finally arrived at Chelsea for his first training session in August, the immediate reaction was that the boy who then was not yet 21, barely looked old enough to be training with the Under-18s, let alone the first team. "Wow, he looks young," tweeted Ashley Cole, in one of his more considered moments on social media.

Yes, Oscar is young, but those who know him in Brazil will tell you that the man himself has been through a lot even before his £25m move to London. Tomorrow at Stamford Bridge, he will face Manchester United, the enduring power of modern English football, as one of the new young attacking talents in Chelsea's team and with the world watching.

Since his early teens in Sao Paulo's academy, Oscar was regarded as having the potential to be the next great Brazilian No 10. His hero Kaka had played for the club and the similarities in their physical appearance and style of play, made comparisons obvious.

"Oscar is a very centred and disciplined character," Rodrigo Weber, an executive at Internacional, the club who sold him to Chelsea, told The Independent. "He knows what he is capable of doing. In Brazil we have lots of players with great technical ability but only some who have the mentality to become a superstar. We could see from the start he was a star player."

Oscar's young career in Brazil was dominated by a court case that threatened to have a serious effect on him. It began more than two years ago when the player and his advisers identified what they regarded as irregularities in his contract with Sao Paulo, with whom he had been associated since the age of 13. Contract disputes are not uncommon in Brazil but this one took a particularly unusual twist.

Oscar's case was heard by the Brazilian equivalent of an industrial tribunal, who found in his favour and ruled that he could be a free agent. In June 2010, at the age of 18, having the pick of Brazil's top clubs, he signed for Internacional in Porto Alegre. But when Sao Paulo appealed to the Superior Tribunal de Justica Desportiva, the problems began.

Sao Paulo won the appeal and the court ruled that he should go back. Given the ill-feeling, that was a non-starter and the clubs came to an agreement of around 15m Brazilian reals [about £4.5m] compensation for Sao Paulo. Oscar had to miss three months of football while it was sorted out.

The Globo Esporte journalist Alexandre Alliatti, who covered Internacional, says Oscar made an instant impression. "From the first he looked like a leader," Alliatti told The Independent. "He asked for the ball all the time. He looks like a very young guy but he has a lot of maturity."

Oscar grew up in the state of Sao Paulo, Brazil's most prosperous, but moved to the city of Sao Paulo at the age of 13 to join the club's academy. He is not, like Ronaldo and Romario, from a deprived background. "Playing football and earning money that way was not like an obligation for him," Alliatti says. "It was a choice."

Despite his talent, he had struggled to hold down a first team place at Sao Paulo. At Internacional he arrived mid-campaign, training with the senior squad but playing for the Under-23s. He also arrived in Porto Alegre in winter, which is cold by Brazilian standards. "At least it has prepared him for London," Weber says.

He won the national Under-23 championship with Internacional and coach Celso Roth picked him for the Fifa Club World Cup in December 2010. Internacional fared badly, beaten by Mazembe from Congo, but Oscar never looked back. He formed a midfield partnership with the Argentine Andres D'Alessandro, once on loan at Portsmouth and now captain of Internacional. "Their friendship had a great effect on Oscar," Weber says. "D'Alessandro is a very strong character and it rubbed off. On the pitch together they were wonderful.

"Oscar married very young [to his childhood sweetheart Laura] and he is very much a family man. He likes to stay at home and play video games or watch movies. Since moving to London he sees a lot of [Tottenham's] Sandro, who was also at Internacional."

As is common in South America, Oscar's registration before he joined Chelsea was half-owned by his club and half by the player and investors represented by his agent. It is no different to Neymar, Lucas Moura and Paulo Henrique Ganso, the man Oscar replaced as Brazil's No 10.

He has 11 caps, and scored twice in the friendly against Iraq this month, and Alliatti says: "If the World Cup was tomorrow, Oscar would be Brazil's No 10". His stunning second goal against Juventus last month is just a taste of what he can do.

"He's a talented player," Chelsea manager Roberto Di Matteo said yesterday. "I don't forget that he's still only 21. I don't want to give him all the responsibilities in the world. He is learning the language and getting used to the high tempo of English football. He's playing for Brazil and all the travelling ... we have to be careful."

Weber warns: "In Brazil we have a very different fitness regime. In Europe, players have to be stronger.

"I hope Chelsea understand that Oscar will never be a strong, stocky player. He will always be a slim, fast, agile player. I watched him in the game against Tottenham and I could see from that alone, he'll be fine in England."

Oscar: From Brazil to Stamford Bridge

* Oscar dos Santos Emboaba Junior was born in Americana, Sao Paulo, on 9 September 1991

* Began his career at Sao Paulo in 2004 aged 13

* Took club to a tribunal due to a contract dispute, walking out after the 2009 season to join Internacional

* Sao Paulo won an appeal on the verdict, leaving Oscar in limbo between the clubs

* After three months without playing, the sides reached a settlement, Sao Paulo receiving about £4.5m in compensation

* Signed for Chelsea in July 2012 and handed No 11 shirt, previously occupied by Didier Drogba

* Represented Brazil at the London Olympic Games, winning a silver medal as they went down 2-1 to Mexico at Wembley .

Elliott Bretland