Andy Murray denies being flat as he works on calm approach

There was no shouting, no angry gestures, almost no emotion of any kind from Andy Murray in his thrashing by Roger Federer at the Barclays ATP World Tour Finals in London on Tuesday - and that is the way he intends it to stay.

The Scot struggled to find his game from the start at the O2 Arena, missing the majority of first serves and returns as Federer cruised to a victory so comfortable it shocked even the world No 2.

Far from being flat, though, as some pundits remarked, Murray revealed it was a predetermined strategy to try to keep his emotions in check - something he has been criticised for not managing in the past.

Murray, who is still in a decent position in Group B thanks to his win over Robin Soderling in the opening match, said: "If I went out there and I smashed the racquet or started shouting, I'd come in and everyone would say to me, 'You were in a bad mood today, mentally you weren't strong enough'. In the match against Soderling I was very quiet as well. I didn't really show much emotion on the court.

"I didn't feel flat on the court. It might look that way when you don't win the match. Maybe it's just very different to what you're used to seeing from me. But that's something that I'm trying to work on, not to let my emotions control how I'm playing. I just tried to stay calm, tried to find a way and it didn't happen."

The opening three days of the tournament in many ways encapsulated Murray's season, with a superb performance against Soderling followed by a pretty abject one against Federer.

The world No 2 was having one of his days where he makes tennis look a ridiculously easy sport, but that was partly down to Murray's failure to put any kind of pressure on him.

Murray admitted ahead of the tournament that he has been inconsistent this year, but he is confident he is in good form ahead of his final round-robin match against David Ferrer today, provided he can sort out his serving and returning. Reflecting on his fluctuating fortunes, he said: "It's disappointing. But it's a lot easier to judge things when you're up against the same player from one week to the next. It's a completely different match playing Roger than playing Soderling.

"I did say that I have been inconsistent this year, but I still feel like I'm hitting the ball fine from the back of the court. It was just serving and returning that needs to improve."

The combination of results so far in Group B means all four players still have a chance to qualify for the semi-finals, although only a thrashing for Federer at the hands of Soderling today could deny the 29-year-old a last-four spot.

Murray will at least know what he needs to do when he takes to the court in the evening. A win for Soderling would eliminate Ferrer and mean Murray must beat the Spaniard and then hope he has a better sets or games record.

Defeat for the Swede against Federer, meanwhile, would leave the home hope needing only to win a set against Ferrer to qualify for the semi-finals.

Ferrer has yet to win a set at this year's tournament but the Spaniard is renowned for his dogged determination and Murray will be well aware of his talents, having lost three of their four matches, including two this year. His defeats have all come on clay, though, with the world No 5 claiming victory in their only previous meeting on hard courts, in Toronto in 2006. Murray added: "It's a very tough match. He's a really tough player and incredibly consistent."