World number one Novak Djokovic, the 2011 champion and who has featured in the last four finals, heads into the US Open with two dispiriting third round losses in Toronto and Cincinnati.
The recently married Serb has also had to bat back accusations that he is distracted by impending fatherhood.
Djokovic, who plays Argentina's Diego Schwartzman in Monday's first round said that he wanted to do better in Canada and Cincinnati, adding that unfortunately he wasn't even close to his best, Sport24 reported.
But, Djokovic said that a lot of things happened in the last two months, and it was very emotional period. He said that he just felt a little bit flat on the court and he wasn't managing to find that intensity and the perfect mindset.
Despite recent hiccups, Djokovic's record at all the majors is impressive, the last time he failed to make at least the quarterfinals of a Grand Slam was at the 2009 French Open.
The odds on Djokovic and 17 Grand Slam title holder Roger Federer meeting in the September 8 final were shortened when defending champion Nadal was forced to withdraw with a right wrist injury, the report added.
