Rafael Nadal's lifelong mentor, his uncle Toni, has opened the door to hiring a 'super-coach' if the 14-time Grand Slam-winner fails to recapture his spark next season.

Toni Nadal said the 29-year-old should consider following Novak Djokovic, Roger Federer and others by bringing in a superstar mentor if the turnaround does not come soon.

Calls for Nadal to abandon Toni blew up after he flopped at both the French Open, a tournament he has won nine times, and Wimbledon during a dismal run this year.

"I think you need to ask Rafael," Toni said at the China Open in Beijing, when asked if Nadal should consider a new mentor.

"But we have a group and I'm the coach of Rafael forever, since Rafael was three years old. Things were always good for us.

"It's true that this year he's going a little down but I am sure the comeback of Rafael is coming soon.

"Maybe if next year Rafael is playing not too good, then I think he can think about some changes in his game or in his team."

Top-ranked Djokovic has flourished since adding Boris Becker to his team, winning three Grand Slam titles this year, while Roger Federer, 34, is enjoying a rebirth under Stefan Edberg.

But Nadal's set-up has always been unusual and Toni, despite his lack of credentials when they started out, has forged a career which has made him one of the most successful coaches in tennis history.

After John McEnroe sparked the debate over Nadal's team, Djokovic was one player who leapt to Toni's defence.

"I don't see a big reason for a change to happen," he said at Wimbledon.

"I think he's (Nadal) going to answer better. But from what I've seen, he's saying a change is not necessary."