World No 1 Novak Djokovic admits he was not surprised to see Andy Murray crash out of the US Open following his straight sets defeat to Stanislas Wawrinka.
The Swiss star dismissed Murray 6-4 6-3 6-2 at Flushing Meadows on Thursday as the Scot struggled to replicate the performances which saw him claim the US Open and Wimbledon titles.
Murray managed to win just nine games across the three sets and failed to earn a single break point, as he crashed out of the tournament at the quarter-final stage.
The defending champion was a shadow of the player who beat Djokovic in straight sets to claim the Wimbledon crown two months ago, but the Serb conceded he has also lacked gusto after major wins.
"It's never easy after you win a grand slam to motivate yourself again to play smaller tournaments and then to prepare yourself again to be mentally, physically, emotionally 100 per cent committed to another grand slam that is basically just a month and a half after his biggest win in his career, which is Wimbledon," the 26-year-old said.
"I have been in this particular situation. I know how it feels. But this is tennis. You definitely learn always something new every single season and you grow as a person and as a player.
"That kind of a mindset to always try to get better on the court, off the court, helped me to understand what I need to do in order to stay number one, in order to always try to win the grand slam titles.
"Because it's a huge competition. All the top players are very consistent. In order to be in the mix for number one in the world or a contender for a major title, you have to be giving everything that you have."
The defeat was the worst of Murray's career since losing to Wawrinka in the third round of the 2010 US Open; although he did maintain his record of reaching at least the quarter-final of every grand slam since.