Andy Murray feels frustrated after disappointment

The season could yet end on a tremendous high for Andy Murray but there was no hiding his frustration and disappointment after he crashed out of the ATP World Tour Finals before the semi-finals once again. After beating David Ferrer and losing to Rafael Nadal, Murray faced a straight shoot-out with Stan Wawrinka for a place in the last four. But the Scot let a lead slip in the first-set tie-break and, although he never stopped fighting, it was not enough to prevent a 7-6 (7/4) 6-4 defeat and an early exit for the fourth time in six appearances at the O2 Arena. Wawrinka now goes through to a rematch of last year's dramatic encounter with compatriot Roger Federer, which ended in acrimony after Federer's wife Mirka heckled Wawrinka with the now infamous taunt of 'cry baby'. Murray said: "I made too many errors. It was tough. I couldn't quite get the balance. Because, when I was going for my shots, I felt like I was making errors."At 4-2 (in the tie-break), I gave a cheap point away. I missed a forehand on the first ball of the rally. It was a fairly basic shot. Then two second-serve returns on my backhand, one into the net, one into the tramlines at 4-3. I made one other error at...