Spain's Rafael Nadal returns a ball to Italy's Fabio Fognini during their final tennis match of the ATP tennis tournament in Hamburg, Germany, August 2, 2015 (AFP Photo/Daniel Reinhardt)

New York (AFP) - Former world number one Rafael Nadal, struggling through what the Spaniard called his worst campaign in 11 years, said Saturday his form is very close to returning to top level.

Nadal has won titles this season at Hamburg, Stuttgart and Buenos Aires, but his record is 42-14 and he has slipped to the eighth seed for the US Open, the final major championship of the year that begins Monday in New York.

"It's a challenge for me to find the feel that I arrived at so many times in my career," Nadal said. "The level of tennis is very close to being back there."

The 29-year-old star has won 14 Grand Slam crowns but this will be the first year since 2004 he has not collected one of the major titles unless he pulls a shocker on the Flushing Meadows hardcourts.

"After a tough year for me, I feel today close to being at the level of tennis where I have been in the past," Nadal said.

"That doesn't mean I'm going to win but in terms of tennis, I'm closer than at any point in the past 12 months to playing at the level of tennis where I've been before.

"It might not be this week or next, but the results will come. The results will be back. I know that."

Germany's Dustin Brown sent Nadal packing in the second round at Wimbledon after he made quarter-final exits at the Australian and French Opens, falling to top-ranked Novak Djokovic at Roland Garros to snap a 39-match win streak on the Paris red clay where he had won nine of the prior 10 titles.





- 'I can be dangerous' -





Nadal, nagged by sore knees for years, lost to Japanese fourth seed Kei Nishikori in the Montreal quarter-finals and to Feliciano Lopez in the round of 16 at Cincinnati in his US Open tune-up events but has built confidence along the way.

"I'm not having the best season personally. Worst season in 11 years," Nadal said. "But I still think I can be a dangerous player in some moments."

Djokovic, a possible US Open quarter-final foe for Nadal as he bids for a third Grand Slam title this year, warned not to underestimate Nadal's champion's heart.

"He puts so much intensity into his game that sometimes his body suffers more," Djokovic said of Nadal. "He's one of the best and hardest-working guys I know. You can't sign Nadal out. He has won 14 Grand Slam titles. He deserves to be among the favorites."

"It's normal he has great respect for me," Nadal said in reply. "That match is in quarter-final. I will have to work a lot to get there."

First, Nadal must get past a Monday opener against Croatia's Borna Coric, who won their only prior meeting last year in Basel.

"He's a tough player. He's a good competitor," Nadal said. "He's a strong player with a good serve and good backhand.

"I don't remember very well that match in Basel but I think I played pretty bad and he played pretty well. Monday, I hope it will be a different story."