Vincent Kompany, Belgium's captain, jumped to head a corner kick during a World Cup qualifying match against Serbia last June. He hoped to land with a goal.

Instead, he fell to the ground with a bloodied face, a broken nose, a fractured eye socket and a concussion.

Still, Kompany remained in the game for an hour after colliding with Serbia's goalkeeper and played the full 90 minutes, his swollen nose packed with cotton. Belgium won the crucial match, 2-1, making its first World Cup appearance since 2002 all but inevitable.

“What wouldn’t you do for your country hey,” Kompany wrote on his Twitter account. The moment crystallised his role as Belgium’s leader and illuminated another aspect of his career, this one less sanguine.

Kompany, 28, is a charismatic and ebullient presence, perhaps the top central defender at the World Cup. He speaks five languages and has a keen sense of social responsibility. But he is also frequently injured.

A groin strain has left Kompany uncertain for tomorrow's second round match against the United States in Salvador. He missed Belgium's final group match against South Korea, along with training on Friday and Saturday.

A team spokesman said his availability for Tuesday was “50-50.” A decision is expected today.

"Vincent is my right hand on the field," coach Marc Wilmots said Friday at Belgium's training camp outside Sao Paulo. "He is very important, a real leader. It is complicated when he is not there. We have others who can replace him, but we will do everything we can to get him ready."

At 6 feet 3 inches, Kompany is a prototypical centre back: smart, disciplined, big, strong, explosive with his first step. He reads the game alertly, positions himself adeptly, tackles assuredly and passes confidently and dependably to start Belgium’s attack.

With Kompany's assertive captaincy, Manchester City has won two of the last three titles in England's Premier League after a drought of 44 years.

For Belgium’s national team, Kompany is the most accomplished of an emergent generation of superbly skilled players, responsible for forging individual talent into a cohesive group.

Many consider Belgium a dark horse in the World Cup, even if its attack has been more plodding than alluring so far. Defensively, the Red Devils conceded a lone goal - on a penalty kick - in the group phase.

"Vincent is a natural-born leader," his fellow defender Jan Vertonghen said. "He's the leader on and off the pitch. That's how everyone sees him. He's not fake. He's like the father of the team, taking care of everything and everyone."

Yet Kompany has also been frequently unavailable because of injury. According to Le Soir, a French-language Belgian newspaper, he has missed 700 days to injury during his 11-year professional career with his club and national teams.

Another newspaper, L’Avenir, calculated that Kompany’s 61 appearances for Belgium might have been 100 by now, except for 39 absences, many because of injury.

During World Cup qualifying, Belgium won three away games without Kompany. Belgium’s team doctor suggested to Le Soir that as Kompany had built his body to accommodate the physical play and demanding schedule of the Premier League, he might have inadvertently become more susceptible to injury, though no more so than any other player.

"He's seen as the leader of the band," said Marc Degryse, a newspaper columnist and retired forward who played in the 1990 and 1994 World Cups for Belgium.

“He’s a motivator. He’s really aware of his responsibility of taking his team forward. That’s his only weak point. He has to stay fit.”

The son of an activist who left the Democratic Republic of Congo as a political refugee, Kompany was born in Brussels and made his first appearance for the Belgian national team at 17. It was not his dream simply to play in the World Cup, he told reporters recently. It was his dream to perform.

"I want to prove something," he said. It may be hard to believe now, but as a teenager, Kompany could be casual toward training, arriving late and sometimes appearing indifferent, said Eddy Snelders, who was an assistant coach for Belgium in Kompany's early years.

But as he moved up the club-team ladder from Anderlecht to Hamburg to Manchester City, his resolve matured with his skills.

“He was not the same Vincent Kompany as he is now,” Snelders said. “He’s taking much more responsibility and he’s much stricter in his behavior.”

And he has developed a social conviction, perhaps unsurprising for someone whose father fled to Belgium after being imprisoned for protesting against the protracted Congolese dictatorship of Mobuto Sese Seko.

Pierre Kompany, his father, later drove a taxi in Brussels and put himself through school to become an engineer, according to news accounts. "My father's story is inspirational for me," Vincent Kompany told The Daily Telegraph in 2011.

“When somebody has gone through this and given you the chance to live another life, you cannot just mess around with it.”

After a visit to the Democratic Republic of Congo in 2007, Kompany raised funds to provide housing, medical care and education for orphans in Kinshasa, the capital. In April, he became an international ambassador for the charity SOS Children's Villages.

Last year, Kompany bought a third-level professional team in Belgium, now rebranded BX Brussels. He said the investment was intended to provide athletic and social opportunities for impoverished children through the club’s youth system.

“The main thing for me is to consider sport at an equal level you would consider mathematics or poetry at school,” Kompany told The Observer, last month. “Its importance shouldn’t be diminished. Everyone has a talent somewhere, and if we can find it in our organization, we will develop it and we will help.”

Most immediately, Kompany is trying to get healthy to play against the United States. Earlier in the World Cup, in reference to the injuries he sustained in last year’s qualifying match against Serbia, he acknowledged, “No one in my family was very happy that I kept on playing.”

But he added: “You have to take emotions and adrenaline into account. Unless someone puts on the emergency brake, you are not going to do it yourself.”

Wilmots, Belgium’s coach, said of Kompany, “He wants to play in this World Cup so badly.”

Tim Howard, the American goalkeeper who plays for Everton in the Premier League, has faced Kompany and Manchester City regularly. "He seems to will that team on at times," Howard said.

“He’s what you want from a captain. He’s always leading the troops. Sometimes he has to lead by example. As a defender, that’s hard, but he finds a way to do it: hard-tackling, stepping in and winning balls, driving the team forward.”

Kompany plays a similarly vital role for Belgium’s national team, whose players have little experience in major tournaments. If he could not play tomorrow, Howard was asked, would it give the United States an advantage? “I don’t know,” Howard said. “He’s the captain and the leader, so that’s always tough.”

New York Times