It would have been understandable if David Luiz had taken the well-travelled road by which Brazilian-born players accept Portuguese citizenship and end up playing for their former colonial masters. In the last World Cup, Portugal's squad featured Deco, Pepe and Liédson, who have all taken that option. David Luiz is virtually unknown in Brazil – he left the country at 19 without playing for any major sides – but worshipped across the Atlantic, especially by Benfica supporters, so "Daveedee'' (that's how the crowds say his name), would certainly fit the bill for a Portugal team with an ageing Ricardo Carvalho and an unreliable Pepe.

That's what the Portuguese football authorities thought anyway. There was even talk of a legal case to bypass the fact the defender has played for Brazil's Under-20s. David Luiz, however, resisted Portugal's call and was rewarded with a starting place alongside Milan's Thiago Silva in a 2-0 win against the USA in August last year. "My dream was always to play for Brazil," he explained in a recent interview. "A World Cup would only be a true experience if I were wearing the Brazilian shirt. Otherwise, it would just be like playing for a club."

After his appearance against the Americans, Luiz ceased to be seen by Brazilians as a mere lookalike of the basketball player Anderson Varejão – who plays for the NBA side Cleveland Cavaliers and also wears a floppy barnet – and became a key figure in the 2014 World Cup project. The fact that the Brazil coach, Mano Menezes, has not recalled the likes of Lúcio, Brazil's captain in South Africa 2010, underlines that. There has also been praise in the media for David Luiz's left foot and his confident displays for the national team, although the defender was certainly not very pleased when Lionel Messi ran rings around the Brazilians to score the winning goal in a friendly with Argentina in Doha last year.

Still, his progress has not been bad for a player who at 14 was told he was too short to be a professional – he is now 6ft 2in and the tallest outfield player in the Brazil squad. Back then, David Luiz still played as an attacking midfielder at São Paulo, a club famous for fostering talent, having produced a series of Brazil internationals such as Cafu and Kaká.

His move to Vitória in 2001 brought a change of position to central defence. Four years later, he had broken into the senior squad and helped the club dig themselves out of the Brazilian third division. It was also a personal triumph for a teenager hailing from Diadema, a town in the greater São Paulo area famous nationwide for social deprivation and police violence.

Benfica came knocking in 2007 and David Luiz was loaned to the former European powerhouse. Ten games were enough for the move to be made permanent by Benfica, who reportedly paid only €1.5m (1.3m) for him. As much as Benfica clung on to the defender when Chelsea first showed interest he represents a huge profit for them.

One thing Chelsea do not need to worry about is David Luiz ending up splashed across the tabloids: he is a devout Christian who names Kaká as a model of professional conduct. Hardly material for tales of drunkenness and debauchery. In Lisbon, he is also known among fans for his approachability and even has his own official fan club, which no doubt helped him become player of the year in Portugal last season – Luiz received 38% of the public vote, his former team-mate, Angel di María, trailed back in second place with only 8%.

If he helps Chelsea stop leaking goals, David Luiz could prove just as popular in west London.