Graphic: How Murray can beat Roddick | Graphic: SW19 in 60 seconds

Andy Murray threw his head back and screamed his delight at his amazing skill: “That was unbelieeeeevable.”

No, not the tracer-bullet serve or the two-handed backhand that have become the trademark shots of his journey to the Wimbledon semi-finals, just a perfectly angled header delivered with the power of Cristiano Ronaldo and the panache of Fernando Torres.

The man with the weight of history on his shoulders prepared yesterday for the biggest match of his Wimbledon career with a kickabout with the lads he calls Team Murray.

You might think that Murray would be uncomfortable having a nation investing in him hours of their television viewing time and extraordinary amounts of money for Centre Court tickets, the jangling nerves causing him to hit tennis balls all over Wimbledon's practice courts with a frenzied determination not to fail the millions who will watch his semi-final against Andy Roddick this afternoon.

But he was more worried about who got to wear the tiny T-shirt - the forfeit for the loser in his game, a mixture of keepy-uppy and tennis without the rackets. Murray was as deadly serious as he will be on Centre Court today and he had more pressing problems at hand, such as how hard to smack the bottom of Miles Maclagan to put his coach off his game. Such attention to detail makes true champions.

Fred Perry was the last Briton to lift the Wimbledon men's singles trophy in 1936. Since then, we have watched generations struggling to meet a nation's expectations, their brows furrowed, their knees knocking as the pressure fried their brains and turned them into mumbling no-hopers.

But Murray could have been on his way to the beach yesterday as, just after noon and with the sun blazing, he strolled out of the Aorangi Pavilion, Wimbledon's exclusive practice area, to make his way down to No16 Court, almost the farthest point from the main complex.

Crowds had formed at the entrance long before he arrived, and a hundred yellow balls and marker pens were raised hoping for the signature of a future Wimbledon champion. Actually, he came out of a back entrance as he walked down the narrow path with Ross Hutchins, his doubles partner, to join Maclagan, Jez Green, his fitness trainer, and Matty Little, his conditioning coach.

Heavy bags were dumped at the side of the court for a serious huddle to take place, just to establish the arcane points system that seems to mean little to anybody apart from this tight group of five.

Hutchins eventually paid the forfeit and was forced to put on the black T-shirt emblazoned with the motto, “Game, Set, Murray”. Could that be the mantra for Wimbledon after his semi-final against Roddick?

It was 45 minutes before Murray picked up a racket and started swinging with that familiar freedom, pinging the ball back at Hutchins and Maclagan on the other side of the net. The ball flew from the Murray racket yet he was obviously operating at half- pace, barely a bead of sweat on his forehead.

Venus Williams walked quietly by, punching the keys of her mobile phone in full Twitter mode; Laura Robson, Britain's young star, wandered along stopping to look admiringly for a few minutes. Jamie, Andy's brother, was 50 yards away, punching serve after serve into an empty court as he prepared for his mixed doubles semi-final with Liezel Huber, his partner.

But nobody looked at them. All the camera lenses were trained on Andy as he laughed and joked through his practice session, a man without a care in his tennis world, even if he stands today on the threshold of history.

Five things you may not know about Andy Roddick

When he was born, on August 30, 1982, in Omaha, Nebraska, doctors at the hospital feared he might not survive because the umbilical cord was wrapped around his neck. It was touch and go for a while and they praised the baby’s remarkable fighting spirit.

He married swimsuit model Brooklyn Decker at a ceremony in his home city of Austin, Texas in April. Two of the invited guests were Stephen Little, the London cabbie who became Roddick’s personal driver a few years ago and has become a close friend, and his wife.

He bites his fingernails and has tried everything to stop, but to no avail.

He hosted the iconic American television show Saturday Night Live in November, 2003, the year he became the US Open champion and world No 1.

He has finished inside the world’s top ten for each of the past seven years and has won at least one tour title for each of the past eight years, a record he shares with Roger Federer.