Novak Djokovic believes Roger Federer is feeling the heat heading into Wimbledon.

Federer was humiliated by Rafael Nadal in the French Open final and the world number one will face his toughest fight yet to retain his Wimbledon crown for the sixth successive year.

Nadal and Djokovic, the Australian Open champion, are strong contenders for the All-England Club title and the Serb is convinced Federer will be concerned by his slight dip in form.

"Federer is still the number one in the world, but suddenly he feels a little bit shaken up because of a couple of losses," Djokovic said.

"It's normal to have ups and downs after four years of absolute dominance. New names are coming, talented players who believe they can beat him and I am one of them. Suddenly he is a little bit worried."

Djokovic, a finalist at Queen's last week, is determined to make up for the disappointment of last year's Wimbledon, when he was forced to withdraw during the semifinal against Nadal because of injury.

"I've been playing some great tennis in the past couple of months," he said. "The final of the Stella Artois Championships gave me even more confidence for Wimbledon.

"Coming to Wimbledon as a Grand Slam champion gives me much more reason to believe I can challenge the top two players.

"Some new names being thrown up as title winners. There are a lot of great players and I think it is going to be much more interesting."

AFP