SO disgruntled with life did Andy Murray appear after going out of the ATP World Tour Finals on Friday night you might have guessed he had just lost a Wimbledon final. In fact, in his mind at least, it felt even worse than that.

The World No 2 has never been the type to show a poker face to the world or let everything wash over him and, while the fringe benefits of this loss included a free weekend to prepare for this weekend's Davis Cup final against Belgum, the Scot insisted the self-inflicted nature of his 7-6, 6-4 defeat to Wawrinka frustrated him more than his 2012 SW19 final reverse to Roger Federer. No sooner was he out of his media commitments than he was back on court, smashing a little yellow ball at his coach Jonas Bjorkman.

"When you make mistakes like that, it is more frustrating sometimes than when your opponent is out-playing you," said Murray. "When I played Roger in the final at Wimbledon, he played great at the end of the match. But when I had my opportunity [against Wawrinka], I wasn't good enough. It was an important week for me and I am disappointed with the way I played."

As conflicted as he feels right now, the Scot has said all along that this coming week is more important than the last one and nothing has changed in that regard. If anything seems likely to cheer him up, what better than the chance to go to Belgium in the company of your brother and your friends to claim what would be a famous victory for British tennis? "Obviously to have something like that just round the corner is good," he said.

While the camaraderie which Leon Smith has cultivated in this team is something to behold, there is a loneliness in being the guy who always has to bear the burden. Andy knows all too well that it is he, and mainly his battle with Belgian's top boy, World No 16 David Goffin, which will decide this tie; he who will have to carry the can if it all goes south. Thankfully, from his first Grand Slam win to that Olympic gold then becoming the first home winner of Wimbledon for 77 years, the Scot tends to regard history is something to be embraced, rather than feared. He usually prefers, though, to wait until he has experienced it before deciding where it would rank in his list of career achievements.

"I don't know how it would feel, to be honest," said Murray. "It is a huge event obviously. But I had no idea what it was going to be like to win my first Grand Slam or Olympic gold or Wimbledon. So I have no idea because I haven't experienced it before. Obviously doing it with your team for your country with my brother in the team, obviously I would imagine it would mean loads to me. I have put a lot of effort into it this year – the whole team has over the last five or six years. So it is great to have the opportunity but I am not getting carried away. I know it is going to be extremely tough, the turnaround is very, very quick and it is going to be far from easy."

Goffin - named by Davis Cup captain Johan van Herck in the Belgian team alongside the veteran Steve Darcis (World No 85), left hander Ruben Bemelmans (105), and young clay court specialist Kimmer Coppejans (135) - reckons the World No 2 will play all three days, meaning he will have to beat him in both singles and doubles to win the trophy. It is a daunting task, but not one he feels is impossible. Highly-rated French coach Michael Llodra has also been lending a hand in the lead-up to the tie.

"It's a really huge event in Belgium because they have been waiting for a final for more than 100 years now," said Goffin, who has lost without winning a set on both occasions the two men have played, including a 6-1, 6-0 defeat in Paris recently. "So I hope the crowd will be completely crazy for me and the team. They are expecting three wins – of course – but the pressure is on all the team, not only on me. I have to beat Andy in singles and doubles - I think he will play the three days - so I’m going to use this pressure to play better and hopefully it will be a great tie for us."