The sun had barely risen on a typical Saturday in Lagos. Yet there was life beneath the concrete overpasses of Nigeria's megacity of some 15m people. Dozens of boys were out playing football, in any space they could find, before the unforgiving African sun got too high.

In the afternoon many headed to makeshift "viewing stations" as the Super Eagles began their World Cup. Match days turn a shack, a fridge of beer and a tiny television into a profitable business. "You have to stretch your neck to see," says Ismaeel Oba, a regular customer. Over in the city's chic districts, a small elite, who mostly work for banks or oil companies, cram into air-conditioned cocktail bars in time for kick-off.

From the top to the bottom, across striking income gaps, Nigerians love this game. It's a no-brainer that young men love football. It's just that there are so many young men in Nigeria. This is Africa's most populous country with some 150m people, over 75% of whom are said to be under 30.

It is also home to the continent's second-largest oil reserves. "Black gold" has made more than $1 trillion for the state since oil was found here more than 50 years ago, by some estimates. Sadly, corruption at the top means that the majority of Nigerians live on less than $2 a day.

Yet the national football team – nicknamed the Super Eagles -inspires patriotism in a country that gives so many so little, with many Nigerians insisting that they will reach at least the quarter-finals of the World Cup. The bookies' are less optimistic, with odds for a win at around 100-1.

One might have expected Nigerian confidence to drop after their first game last weekend, which they lost 1-0 to Argentina. Instead, the goalkeeper Vincent Enyeama has been feted for a series of excellent saves that prevented a more crushing defeat. At one sweltering viewing shack in Lagos, young men raised beers and shouted praises in Yoruba, a language spoken by the country's patchwork of ethnic groups. Cries of "Boy yen o mo play!" – "that boy knows how to play!" – sang out.

But tension is now building ahead of Thursday's game against Greece, which Nigeria must win to keep alive their chances of surviving the group stage.

Lars Lagerback, Nigeria's manager, has generated much debate since taking over in February. Pundits query the timing of his appointment, which gave him little chance to get to know his players before the tournament. "It's like a general going to battle without knowing his troops," says Nnamdi Okosieme, sports editor of Next, a Nigerian newspaper with a young and urban readership.

Lagerback has also gone into battle without the man who could have beenhis best soldier. The Chelsea midfielder Mikel John Obi, Nigeria's most famous player, dropped out of the contest just days before the opening ceremony due to a knee injury. Other big names are thin on the ground.

The 23-man squad features players from Everton, Marseille and Dynamo Kiev. None play for a homegrown team. Unfortunately, Nigeria's domestic league is a shambles that rarely retains the country's best footballers or most ardent spectators. The Lagosian boys playing soccer beneath the traffic at dawn are obsessed with the Premier League and La Liga. The radios in the cars overhead are tuned to Chelsea games. European teams have the cash to buy better players and provide better entertainment, fans say nonchalantly.

In recent years, some retired Nigerian football stars have set up free soccer academies to nurture local talent. The schools are yet to yield big results. "The academies are still young and it is too early for them to produce stars," explains Kelechi Eke, an independent agent and talent scout based in Lagos. "But they are giving good players to the under-17 team."

So, in this World Cup, Nigeria remains an outsider – Ghana and the Ivory Coast, its smaller and poorer neighbours, are stronger contenders.

Nonetheless, Nigerian optimism – sorely tested by daily life – is hard to dent. Many still hope today's team can recreate that mid-1990s heyday when they won the Africa Cup of Nations and Olympic gold. "We have a knack of not preparing but then doing well when we get there. We always get out of jail," says Okosieme. "There is a phrase here that God must be a Nigerian. It's a popular among our football fans – and our politicians."

This is not a news report and may contain views expressed by the author which are not supported by GNM.