As Andy Murray slumped in his chair here in the early hours of yesterday morning, there was little he could focus on other than the disappointment of losing.
The main source of consternation was the realisation that he was unable to match the world No.1 Novak Djokovic physically for longer than the first two sets of their US Open quarter-final as he went down 7-6, 6-7, 6-2, 6-4 in three hours, 30 minutes.
But there was also optimism over the way in which he matched the world No.1 point for point, moving freely and with his forehand looking as good as it's ever been, if not better.
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With four months to go before the Australian Open, his next crack at a grand slam title, the 27-year-old will mull over a season that, by his own high standards, has been a notch down from where he wants to be.
Having recovered from back surgery last September, the Scot reached at least the quarter-finals of all four grand slams, with his best effort a semi-final on clay at the French Open, traditionally his weakest surface.
As the former Wimbledon champion Richard Krajicek pointed out to the BBC, those achievements are hugely impressive for someone who underwent a back operation a year ago, however supposedly 'minor' it was, in surgical terms.
Darren Cahill, the former player turned coach and ESPN pundit, who has worked with Murray at times, said yesterday he didn't think it would be too long before he was back to his very best.
"As far as I'm concerned I would take a lot more positives out of last night than I would negatives," he said. "I thought for a couple of sets it was the best tennis I've seen him play since Wimbledon and for certain [parts] of that match he may actually have played better than he did when he won Wimbledon."
Cahill said Murray's inability to sustain his level across the four sets was a concern but something he would almost certainly improve over the coming months as he gets more matches under his belt.
"I look at his form and his physicality from January until now and he's way better now," Cahill said. "And I would say that come London, November time [and the Barclays ATP World Tour Finals], he's going to be a different player again and he's just going to continue adding to his tennis game."
Having spent three and a half hours more on court than Djokovic on the way to the last eight, Murray was always playing catch-up against probably the fittest man on the circuit and the brutal, gruelling rallies, many of which lasted more than 20 shots, took their toll.
Cahill said the stress of overcoming body cramps in his first-round match against Robin Haase may also have been a factor.
"When something like that happens, you feel like: 'well, if it happened today, it could really happen any day,'" he said. "You start to manage your movement around the court a little bit to protect yourself, so it doesn't happen again and then you start cutting corners and you really don't want to do that.
"But nobody works harder than Andy off the court. He turns over every stone he can to be as good an athlete as he can be. He's not a good athlete - he's a great athlete. So I'm sure he'll get to the bottom of it."
What will have pleased Murray most is the way that he took the attack to Djokovic after the first set, hammering his forehand with real venom. Another of Murray's former coaches and another ESPN pundit, Brad Gilbert, was also hugely impressed.
"The first two and a half sets Andy hit the ball as cleanly as I have seen him do it in a long time, he hit the forehand hard but maybe it took its toll," Gilbert said. "The serve, forehand and backhand package was Andy at his very best. It seemed like his back stiffened up towards the end. I'm confident that within a year from now he'll be back in the top three."
As he flew back to London yesterday, Murray said he was anxious to get another crack at adding to his two grand slams.
"I think I can do better," he said. "Yeah, it was a good tournament and I played some nice tennis at times. There are definitely a few things I can do better to keep working on and improving. But it's a shame. Obviously the slams are over for this year, so I have to wait a few months before the next one."
Murray will play one tournament before the next Masters 1000 event in Shanghai, either in Beijing or Tokyo, as he looks to end the season on a high. He is just outside the eight qualification spots for London but with no points to defend from here on, it would be a surprise if he does not make it. However, Murray said he was unlikely to chase a spot by playing extra tournaments.
"To be honest, [qualifying] was not a massive goal of mine," he said. "It's obviously nice to qualify. It's a good tournament. I played a number of years and enjoyed it. I don't want to overplay. I'll likely play a tournament before Shanghai. I'm not sure exactly which one yet. [But] I won't expect to overplay just to try to qualify."