He fires in the aces but he can also crack the one-liners. Andy Roddick is a serious contender on court. He is also the best server of humour in the post-match press conferences.

He fires in the aces but he can also crack the one-liners. Andy Roddick is a serious contender on court. He is also the best server of humour in the post-match press conferences. As befits a personality who has hosted Saturday Night Live, Roddick has a sense of timing off-court as well as on it.

He may be remembered for playing in two Wimbledon finals (2004, 2005) but for this observer he will always be recalled with affection for his response to one of those interminable, daft questions posed by a countryman.

It was the rainswept Wimbledon of 2007. An American voiced piped up. "Andy, there has been talk of playing the men's final on a Monday because of the delays. If this goes ahead, and if you reach the final, will you stay on?" Roddick's reply was swift, if not Wildean: "Goodbye." And with one bound, he was outta there.

This showed that the man from Nebraska has a low tolerance for silliness and a ready retort for any question. He is, too, a player who is dedicated to extracting the most from his talent. He has an appreciation of the history of the game and is desperate to be part of it.

One grand slam title has whetted his appetite, not sated it. And that US Open in 2003, seems a long way away. It was in the far-off days before Rafa rose, Novak soared and Andy emerged.

At 26, Roddick has assumed the rank of veteran with the progression through the ranks of Nadal, Djokovic and Murray, who are all four years younger than him.

He has tried to adapt.

His game is still dependent heavily on the serve. With Sam Querrey and Ivo Karlovic, Roddick has clocked the highest speed on serve at Wimbleon. It rattled past at 141mph. But he has also dedicated himself to a fitness regime that has made him sleeker and fitter at Wimbledon 2009. His improved physique and his serve will be crucial to any chance he has against Murray.

The received wisdom is that the Scot has Roddick's number, that he will move him around and win comfortably. Murray has won six out of their eight meetings. The American, understandably, has a different view.

"It was a dogfight and the next one will be," said Roddick after he trudged off finally defeating Lleyton Hewitt after four hours and five sets on Wednesday night.

"It only gets tougher from here on and Murrray is playing great, but I will have fun and look forward to competing," he added.

Murray is priced at 1-4 to go through to meet the winner of Roger Federer and Tommy Haas but Roddick is relaxed about that assessment. "He starts as favourite because he has been in better form in this tournament. But you don't get points for previous matches. I will go in and have a go," he said.

This may read as the words of a plucky loser but they were said with quiet strength. But Roddick knows that Murray is an excellent strategist with a facility for mercilessly exposing the slightest flaw in an opponent.

"He is complete, no real weaknesses," said the American of Murray. "His biggest strength is he has a really good tennis IQ.

"He really plays for the next shot. It is something you have to deal with for five sets."

This is business talk. The humour resurfaces quickly.

How will Roddick go about beating Murray?

"Very carefully," he replied.

Roddick has already said that he has a cunning plan for neutralising Murray's support on Centre Court. "When they shout C'mon Andy', I'll pretend they are supporting me."

He pointed out that the support for Murray has a double-edge. "It helps you dig deep in a tough match," he said. "But it also comes with a little bit of pressure."

The pressure, though, has hardly seemed to touch Murray. It rises again in intensity today, though. The American can make light of most things but he is aware that the heaviness of his serve gives him a fighting chance.

"With my serve I can give myself a chance in any match,"

he said. "I have been in this situation many times. I am not going to predict anything."

The joking is over.

Let battle commence.