The world's number one tennis player, Roger Federer, suffered a shock defeat in his opening match at the Masters Cup tournament in Shanghai.
In an interview with swissinfo shortly before the three-set loss to Fernando Gonzalez, Federer criticised the busy men's tournament schedule.
Federer is eager to prove he's not slipping after losing consecutive tennis matches for the first time in four-and-a-half years, but going into the match against Gonzalez, he admitted that "I am not entirely happy with my form".
Federer lost to the Chilean number 7 seed 4-6, 7-6 (1), 7-5 at the Masters Cup to snap his 15-0 record in round-robin play at the season-ending tournament. It also was the defending champion's first loss in 11 meetings against Gonzalez.
Federer now will likely have to beat Andy Roddick and Nikolay Davydenko to reach the semifinals.
swissinfo: Whom do you consider your strongest opponent?
Roger Federer: My biggest rival still is Rafael Nadal. This is clearly the guy I had the most rivalry no matter what kind of surface.
swissinfo: Are you worried that you will lose the number one position to Nadal?
R.F.: Yes, maybe a little bit after Wimbledon, when he had a great run on clay and also on grass. It was very tough... to beat him in the Wimbledon final. This was really when I thought, if I don't play well during the US Open, it would be very difficult for me. Again, I stepped up, played well and will finish this year as number one.
swissinfo: How about next year?
R.F.: It is going to be difficult for sure. Nadal is a good player and I never see him playing badly. His injuries are his biggest problem. He has problems with his knees, maybe with his hand, I don't know exactly. But having great battles with him is great for tennis.
swissinfo: What can stop you from winning?
R.F.: I hope not an injury! I hope I stay fit so I have many more years to come. But still, there will be juniors coming up. I like playing against different generations and having battles with different players like Andre Agassi, Pete Sampras, Leyton Hewitt, Marat Safin, Andy Roddick and Nadal who all challenged me. Some have beaten me more, some less. But I like to be around and always enjoy the challenge.
swissinfo: Some say there are way too many tournaments on the men's tour.
R.F.: I agree - maybe a little bit. Maybe it's better to play a few tournaments in a run... take enough vacation and preparation. I only play about 18 tournaments a year; other guys play 30 tournaments. Of course when I play, I win a lot, so in the end I also play about 80 matches a year, which is a lot.
swissinfo: How long will you continue without a coach?
R.F.: I don't know. I am definitely considering the coaching situation. Coaching and hearing some feedback is important, but I am still not sure when and who it's going to be.
swissinfo: 2008 is going to be a sports highlight for China with the Olympic Games in Beijing. Is it also a highlight for you?
R.F.: Yes, absolutely. This is one of my big goals next year. The Olympic Year is very special. But also a tennis year has many highlights. Of course there's Wimbledon, the Australian and the US Open, the French Open and hopefully the Masters Cup in Shanghai again.
swissinfo-interview: Fabian Gull in Shanghai
Roger Federer has led the world rankings of the ATP (Association of Tennis Professionals) since February 2004.
In 2007 he won seven titles, including three Grand Slams - Australia, United States and Wimbledon.
The ATP named Federer "Player of the Year" for the third year in a row.
He was Swiss sportsman of the year in 2003, 2004 and 2006.
Federer has been an ambassador for the children's aid organisation Unicef since April 2006.
Date of birth: August 8, 1981
Plays: Right-handed, single-handed backhand
Turned professional: 1998
Titles: 52 (Grand Slams: 12)
Prize money: $36,007,078