On Saturday afternoon millions of television viewers, 80,000 Twickenham fans and 45 players will have a flutter of nerves as South Africa and New Zealand prepare for their World Cup semifinal — but not Springboks flanker Schalk Burger.

Not because he does not care about the outcome — ask any of his opponents over his 12-year Springbok career about that — and not because he is unused to a big match atmosphere — this is a man who has won a World Cup final and helped his country beat the British and Irish Lions.

It is because his battle with a life-threatening illness, as well as the arrival of two children, ensures he always remembers that rugby, for all its importance to him and to his nation, remains no more than a game.

Burger's story has been well documented but it bears telling again just as a reminder of how far he has come to be back in the mix in a World Cup semifinal.

Early in 2013 doctors found a cyst on his spinal cord but during treatment he picked up an infection — bacterial meningitis — contaminating his spinal fluid.

For days there were fears he would not survive but, after five operations, he pulled through. Having gone into hospital as a teak-tough 110 kg, he emerged six weeks later as a 90 kg "bag of bones.

A long, slow and often painful battle to regain health, strength and fitness followed, the first eight weeks of which he had to stay indoors.

Playing rugby seemed a distant dream but he eventually resumed his club career, then returned to the Springboks bench in June 2014 — two-and-a-half years after his last game in the 2011 World Cup.

It was not long before he regained his starting place and, now as vice captain to Fourie du Preez, he has been an ever-present at the World Cup and produced a man-of-the-match performance in the quarterfinal victory over Wales.

"Rugby pretty much dominated my life, it was 80 percent-plus," Burger, 32, said on the eve of his fourth World Cup.

"Whatever I did revolved around rugby. But now I see it as a much smaller part of my life, maybe 20 percent. There is much more to life."

It might not look that way when his distinctive blond locks are seen all over the pitch, smashing into rucks, driving the ball over the gain line and tackling anything that moves from first minute to last.

"The great thing about Schalk is that for him just to be alive is great," coach Heyneke Meyer said on Wednesday.

"That why he's so relaxed. He's always smiling, right before the match, and I think he's not ready, but when he goes on the field he's like a different human being.

"Schalk's workrate is immense, he's probably the fittest he's ever been. He adds so much around the park with his play and his leadership.

"But he says he plays just to have a beer with his mates."

One of those mates is Victor Matfield, who has been in the forward trenches and shared many a beer with Burger during the last dozen years.

"Sometimes we take things for granted — I thought my hamstring injury was the end of the world — but things like what Schalk's been through put it in perspective," Matfield said this week.

"As a player he's been outstanding — he's had the most carries in the tournament and can distribute well now.

"He also really brings that calmness, especially before the game.

"He's just a great guy who just loves to play rugby."