The setting is the bottom of an unpretentious street, a drop-shot’s distance from Selhurst railway station in South London. Andy and Jamie Murray are at Heavers Farm Primary School, talking anything and everything to kids whose faces are painted in Union Jack colours, who scream hysterically and wave flags.

Jamie, all cheeky chappy charm, is more at home in these surroundings; he has a natural empathy and Andy looks happy to be in his brother’s shadow for a change. A few hours earlier, Andy had been modelling his new Fred Perry gear in East London and when he walked on stage he did not know whether to smile or where to put his hands.

Why hadn’t someone given him a racket was one’s first thought. Andy Murray with a racket in his hands is a man transformed. Andy Murray with a racket in his hands is not in the least flustered. Andy Murray with a racket in his hands is a champion, perhaps one day very soon a grand-slam tournament champion.

Tomorrow, with said racket rolling through his fingers, Murray will begin his fourth Wimbledon Championships against Robert Kendrick of the United States, eminently a contender. The Scot has been a quarter-finalist and, since last year, has contested a US Open final and done better in the French — reaching a quarter-final — than before. His career is on the up.

As we slip into a couple of chairs made for infinitely smaller people, there is a sense that everything is under control. Murray could not look more ready, eager or honed. But there are questions and more questions. It is the way of the world the week before Wimbledon. Can you? Might you? What if you did?

“One of the things I don’t like is when someone starts a question with ‘you have to be feeling the pressure, you have to be feeling the expectation,’ ” he says. “But you don’t at all. It’s like, come on, I know what is going to be written, I know what everyone is going to say. Regardless of whether I had won Queen’s \ or not \, the same things were going to be said. It comes around every year and it means absolutely zero.

“It’s an excuse people can use if they want — ‘oh I would have won the match, if only you guys hadn’t written all that because I felt the whole nation was putting so much pressure on me’ — but it is on the court where I feel most comfortable. I really don’t feel the weight of expectation, it’s the last thing you are thinking about when you are hitting your first serve of the match. When it comes down to it, playing in front of 15,000 people on Centre Court at Wimbledon is what I want to do, that’s the part of your job you enjoy the most.”

One wonders what he was like as a kid, an apple of-the-teacher’s-eye type, thrusting up a hand to ask a question? “I was energetic, like these kids today, but I was quite quiet,” he says. “But I loved doing sports. I wasn’t at the front of the class, I spent more time at the back looking forward to going home to play.”

J. K. Rowling was the most famous person he recalls visiting his school. “She read out a couple of chapters from the first Harry Potter book,” Murray says. “I read the first two myself and got through a bit of the third but I’m not much into books. I had to read a few of the proofs of mine but that’s about it.” I recommended Jon Henderson’s The Last Champion, the Life of Fred Perry, published recently to coincide with the centenary of the great man’s birth, which Murray had celebrated with his new clothing line. “Yeah, OK, I’ll read that,” he promises.

Where Murray’s own life will lead from here might be one for Rowling’s imagination. At 22, he is on his third coach since leaving the junior ranks in 2004, having dispensed with the services of Mark Petchey and Brad Gilbert, before hiring Miles Maclagan in late 2007, to profound effect. From the outset, Murray has known where he was headed and that the journey would bring its fair share of dramas.

“There is a transition period from 17, 18 when you need a coach in control, because you aren’t mature enough to know what to do, how to warm up, how to get your racket strung, the bits and pieces,” he says. “By 20, I was grown up, I knew what I was doing on the court, I needed it to be more fun but I also needed to know why I wasn’t fit enough, why I was getting niggly injuries and since I started to do my own thing and hired the team I wanted, it’s worked out really well.

“When Petch [Mark Petchey] was head of men’s tennis at the LTA, I remember him flying up to a Futures in Edinburgh and I lost one and two [6-1, 6-2] to Mark Hilton. He said he was sure I’d be a top-ten player. He said that after having seen me get smashed. Petch kept in touch when I was in Spain, always positive, and the LTA were funding me a bit then so I hired Mark to travel. It worked well but it ran its course. I had a lot of respect for Brad as a coach but he dictated everything and after a while I didn’t feel that was what I needed. I didn’t feel I was being listened to and in an individual sport, that wasn’t correct.”