"I made the commitment with the event, the city, with myself... I tried... I cannot keep going. It really doesn't make sense."
Rafael Nadal's withdrawal from the ATP World Tour Finals late on Monday evening wasn't a surprising outcome and he should be applauded for turning up at the season-ending event.
With the world No 1 ranking in the bank and his financial future secure, a half-fit Nadal did not need to show up in London. His team had advised him to give it a miss, but then the 16-times grand slam champion has never given less than his whole body and soul.
One main topic dominated the main build up the event. Would Nadal be fit enough to compete at the O2? Nadal pulled out the Paris Masters ahead of a quarter-final appearance due to a right knee injury and, in all honesty, would've been well within his rights calling time on his season there and then.
Nadal instead felt a duty of care to fulfil a commitment to the organisers of the tour and his allegiance of fans to compete.
The ATP in equal measure gave Nadal as much time to recover, scheduling his opening round-robin match against David Goffin on Monday evening. While his movement was stilted and he was clearly in physical pain, Nadal demonstrated all of his fighting qualities to save four match points and take the match into a deciding set.
Nadal's grimacing became more intense as the third set wore on and after two hours and 37 minutes on court and a 7-6, 6-7, 6-4 loss, the 31-year-old had already decided he would have to pull out.
The Spaniard ended his press conference in his typically gentlemanly fashion with his sign off. "Thank you and Merry Christmas everyone".
While fans who had bought tickets for Wednesday and Friday and the weekend in the hope of watching the 10-times French Open champion in action, will be disappointed, they will be able to look at the bigger picture.
The sad issue is that it has become a familiar story in London. Nadal has qualified for the season-ending finals 13 years in a row, but last night's withdrawal became the sixth time he has either pulled out during the event, or failed to be fit enough to compete.
His appearance in the capital this year, though, could yet jeopardise his chances of being fully recovered for the Australian Open in January and left pundits including Greg Rusedski to question whether he should have given the Finals a miss altogether.
"He made a commitment to this event, he said 'I'm going to try and play one match'. I think before this match, had it not been the ATP Finals, I don't even think he would have played," Rusedski said.
"So in Paris the injury was already pretty bad. Maybe he took some pain killers or got an injection and said 'I'm going to play one match and that's it'. In retrospect you wonder whether that was the right decision."
Nadal's withdrawal widens the door for favourite Federer to win a seventh World Tour Finals title in his 15th appearance.
Federer hasn't had a complete clean bill of health in the second half of the season but has been able to pick and choose his events by putting his own needs first.
His late withdrawal ahead of the Paris Masters drew criticism from director Guy Forget who took a thinly veiled swipe at the legendary Swiss.
Forget was disappointed that Federer had put a 500 event in Basel ahead of the 1000 points on offer in the French capital.
"The tennis player, by definition, looks at his own interest, what interests him, what interests him less and has to make choices," he said.
Equally, Federer gave the clay-court season a miss to focus his efforts on winning Wimbledon - a decision that was validated with his eighth gold cup in July. Nadal, however, has not yet felt the urge to cherry-pick his tournaments, and despite an injury-ravaged career, at five-years younger than Federer still feels he can cope with the rigours of the tour.
This is not to question Federer's methods and decisions. At 36-years-old he has to be mindful of what's round the corner.
Both Federer and Nadal have given so much to the sport and to fans around the world that they need not justify their actions.
All that we hope is that Nadal has not caused himself further damage by pleasing fans and organisers in London that he can compete on a level-playing field with Federer again in 2018 - and at a time when Novak Djokovic, Andy Murray and Stan Wawrinka are fighting fit again. What a season there could be in prospect.