Jamie Delgado
Former Great Britain Davis Cup player

When he is on, he does have the power in his game and quality to beat the best in the world. He's just not quite as consistent as the other guys. Tonight is going to very tough for Andy.

(Speaking on BBC Radio 5 live sports extra)

Image source, Rex Features

They have cranked the hype meter to 11 tonight at the O2.

Before the two players emerge from the bowels of the O2 Arena, the crowd is treated to a rendition of William Ernest Henley's Invictus - you know, the I am the master of my fate, the captain of my soul one used recently in a computer game advert - voiced by a Brian Blessed sound-a-like.

Wawrinka and Murray look almost a little sheepish as they finally make it out on court.

Image source, Getty Images

If Stan Wawrinka does prevail, we lose a British interest in the last four.

However we gain a tasty little reunion.

Last year at the semi-final stage, Wawrinka lost to Federer 4-6 7-5 6-7 (6-8) after failing to convert four match points.

It emerged after the match that Wawrinka had complained during the contest that Federer's wife Mirka was trash-talking him between points, allegedly calling him a "crybaby", among other things, , external

Wawrinka and Federer had to pair up the following week for the Davis Cup final. It could have been awkward. In the end it was victorious with Switzerland beating France in Lille.

Novak Djokovic brought his pilates ball last night.

Andy Murray has come armed with some chest-stretching bands today.

I'm half expecting to see Stan Wawrinka rolling about on some ab-crunching device bought off an shopping channel in a moment of late-night optimism.

Let's hope they have remembered their bats.

Image source, Getty Images

BBC Radio 5 Live Sports Extra

This match is live on BBC Radio 5 live sports extra.

You can get across their words of wisdom on this very page. Just click on the audio icon or live coverage tab at the top of this page to unleash a stream of aural excellence.

Piers Newbery
BBC Sport at the O2 Arena in London

Image source, Getty Images

It was a stinking hot New York afternoon, Sir Sean Connery was courtside, and Murray was giving it the full repertoire of verbals and racquet smashing - his last meeting with Wawrinka in 2013 was one to forget. The Briton was the reigning US Open champion and fresh from landing the ultimate prize at Wimbledon, but he went down tamely to an inspired Wawrinka. Things were considerably frostier a couple of hours later in his press conference. "I was playing well enough to get to the quarters," said Murray."It's not an easy thing to do." 

Image source, Getty Images

Andy Murray leads the head-to-head history against Stan Wawrinka, having won eight of their previous 14 meetings.

Wawrinka has bagged the last two though, both in straight sets.

This will be the pair's first match in more than two years.

Image source, Getty Images

The man who will help decide Andy Murray's weekend plans is Stan Wawrinka.

Like Murray, the Swiss world number four has beaten David Ferrer and lost to Rafael Nadal so far at the O2.

Tonight's match is a straight shoot-out. The winner gets a prime Saturday evening semi-final slot against Roger Federer. The loser collects their chips and heads for the door.

Piers Newbery
BBC Sport at the O2 Arena in London

"If he’s mentally not really here, then he’s a different player.” That could have come from the mouth of either of tonight's players, but it was in fact Wawrinka on Murray., external The Swiss is hopeful that Murray will have one eye on the Davis Cup final, a situation he experienced 12 months ago. "After one or two days, I was ready for it," he added. "I was 100% focused here because it was important for me, then I switched in two days."

Image source, Getty

Britain will compete in their first Davis Cup final in 37 years next weekend. It is 79 years since they actually won the thing.

Therefore, you could understand if Murray, the key man in Leon Smith's team, decides he would rather get down to some clay homework than hang around at his eighth straight ATP World Tour Finals

On the other hand, a chance to take on old smoothie Roger Federer in a semi-final under the O2's Saturday night lights?

Those sort of opportunities will not crop up many more times in the 28-year-old's career.

Image source, Getty Images

Mayo or brown sauce?

Moules or whelks?

Tintin or Sherlock?

No doubt that Andy Murray is in London in body, but has his mind hopped over the Channel to Belgium to focus on Great Britain's historic tilt at the Davis Cup next weekend?