Djokovic targets US glory
Defending champion Novak Djokovic insists he is "physically stronger and [more] prepared" for the US Open than he was 12 months ago.
There have been reports that personal problems have affected the Serbian world number two, speculation Djokovic has been quick to deny.
The Serbian star won the Australian Open earlier this year but has failed to match his exploits of 2011 and lost the French Open final to Rafael Nadal, missed out on a spot in the Wimbledon final and also couldn't pick up a medal at the Olympics in London.
However, there have been signs the world number two is close to rediscovering his best form after winning in Toronto and reaching the final in Cincinnati.
The 25-year-old insists he is in confident mood ahead of the US Open and hopes to successfully defend his crown.
"I love playing in this tournament; the last five years I have had lots of success. It's incredible and a very unique feeling to come back to New York as defending champion," Djokovic is quoted as saying by ESPN.
"It's been a long season and a long summer, but my year has been really good. I actually try to always look from a positive side.
"I do feel physically stronger and [more] prepared than I did last year. Mentally I had some ups and downs throughout the season, but I think that was maybe expected in a way. It's normal to have ups and downs."