Is Brazilian wonderboy Neymar worth £40m or is he an Abramovich indulgence?

Roman Abramovich is no stranger to parting with the odd fat cheque (think Andrei Shevchenko, £32m or Fernando Torres, £50m). Neither – thus far, in Torres' case – are rip-roaring success stories with the former scoring nine league goals and the Spaniard one in 18 for Chelsea but despite having his fingers singed the club's owner Abramovich is preparing to spend big again this summer, now that his new manager Andre Villas-Boas has safely been tempted from Porto. Attacking football is the new mantra, and it does not come cheap.

Chelsea have already bid £22m for Tottenham Hotspur playmaker Luka Modric, while they are also hoping to tie up deals for striker Radamel Falcao, whose buy-out clause is €30m (£26.7m), and midfielder Joao Moutinho whose price is set by Porto at €40m. Then there is the pursuit of Neymar, the Brazilian teenager whose value exceeds them all after Santos put the sum of €45m as the price of buying him out of his contract.

The first three names are established players, which makes the club's pursuit of Neymar all the more intriguing, and all the more risky. Are Chelsea sure he is worth the cash? Or would his signing be more of a statement of intent from Abramovich?

In the past year, since Brazil's failed attempt to win the World Cup, Neymar has become the new superstar of the team. He is the next shining idol to wear the yellow and blue, and all eyes will be on him as Brazil aim to retain their Copa America title which starts on Friday in Argentina.

Chelsea face stiff competition from Real Madrid for his signature, but whoever does land Neymar will sign an exceptional footballer and will have the challenge of trying to nurture that talent into a world star. Although he is slowly convincing doubters that he has the determination and strength to match his undoubted flair, Neymar is still only 19 years old, with just five international appearances to his name.

Spending large sums on teenagers has not been Chelsea's style, although they did lay out £16m on John Obi Mikel in 2006, but it is a tactic that has worked well for Manchester United. Sir Alex Ferguson did not think twice about spending £12.25m to bring the unknown Cristiano Ronaldo, then 18, to Old Trafford in 2003; just as he did not shy away from paying out £25.6m to bring an 18-year-old Wayne Rooney to United a year later. He has now added 19-year-old Phil Jones to his squad from Blackburn, for £16.5m.

Chelsea may be trying to go down the same route: the potential return in signing Neymar is enormous. If he justifies the hype and delivers on his potential, then he could prove to be an excellent signing. Ronaldo's success at United has demonstrated that flair players can thrive in the Premier League, despite the image of it being a physical division. Neymar showed he could handle some rough stuff when he played against Scotland in London earlier this year.

Chelsea also already have an influential group of young Brazilians that would help Neymar to settle in. Alex, David Luiz and Ramires are all regulars, while Lucas Piazon, another teenage Brazilian, is to join in January from Sao Paulo once he turns 18.

The Neymar excitement is close to fever pitch in Brazil in the build-up to the Copa. "I prefer Neymar to Messi," said Neymar's Santos team-mate Elano, the former Manchester City midfielder. The Brazil manager, Mano Menezes, who dropped Neymar for disciplinary reasons after his goalscoring debut against the USA last year, has also been somewhat over-the-top recently. "This is not the first time a special national team player is born. We have that privilege of having great Brazilian players, as is happening now with Neymar, and thank God almost all of them got to where we hoped they would. We hope that will be the same with Neymar," Menezes said.

There have been enough false dawns, however, to justify any reticence in spending upwards of £40m on such raw talent. From Mirandinha to Denilson, there are countless Brazilian players who have packed their bags and traveled to Europe but for one reason or other have left their individual brilliance behind in South America.

Of all the cautionary tales concerning unfulfilled talent, one stands out. A young striker known as Keirrison came from nowhere to top the Brazilian goalscoring charts at the age of 20. His performances for Coritiba and Palmeiras caught the eye of the Barcelona scouts, and he moved to the Nou Camp for £12.5m in 2009, dreaming of emulating the likes of Ronaldo, Ronaldinho and Rivaldo in the scarlet and blue stripes. Two years into his five year deal, Keirrison has yet to make his debut and is up for sale after disappointing loan spells at Benfica, Fiorentina and Santos.

Chelsea are wise to be cautious. However, the club have done their homework on Neymar, who has the endorsement of Abramovich's personal scout Piet de Visser. The veteran Dutchman is said to be the man who brought Romario and Ronaldo to PSV Eindhoven. Tough act to follow.

The two sides to buying a prodigy

Some pay off...

Wayne Rooney Just 18 when he moved from Everton to Manchester United for £25.6m, still the world record fee for a teenager, in the summer of 04. Scored a hat-trick on his debut, and has not looked back since.

Sergio Aguero Signed for Atletico Madrid from Independiente aged 18 in 2006, for £20m. Aguero has scored 102 goals in 234 games for Los Colchoneros and has seen his transfer value soar.

Alexandre Pato Milan paid Internacional £21m for Pato even though he was just 17 in 2007. He has developed into a vital member of a team that won Serie A last season.

Others don't...

Denilson Real Betis set a new world record when they spent £21.5m on Sao Paolo's 20-year-old Brazilian midfielder in 1998. Despite being a World Cup winner in 2002, his career was a huge disappointment, and he even failed to secure a contract with Bolton Wanderers after having a trial with them in 2009.

Antonio Cassano In 2001, current England manager Fabio Capello spent around £20m to bring the explosive 19-year-old striker from Bari to champions Roma. After five years of rows and controversy, Cassano was sold to Real Madrid for £4m. Has recently rebuilt his career with Milan.