Rafael Nadal is 'playing spectacularly' this season and he is capable of even greater consistency than Novak Djokovic, says Todd Martin.
Nadal started the season in breath-taking form, and has already won both the Australian Open and French Open despite battling foot and rib injuries.
He was unsure of whether he would be able to play Wimbledon at all this year due to his foot problem, and he started the tournament in unconvincing form.
However, he is now looking much more at home, and former Australian Open and US Open finalist Martin says Nadal is capable of consistency that even Djokovic can't match.
"Rafa is still incredibly consistent, even when he's playing 5 to 10 percent below his best level.
"He is still insanely focused, and that's why I think we see more ups and downs from Novak Djokovic than we do from Rafa."
Rafael Nadal required painkilling injections at Roland Garros to get himself through the matches, and he said that was not something he would be prepared to do at Wimbledon.
He has undergone radiofrequency treatment instead, but there remains a fear it may not provide a lasting solution.
"Only Rafa knows how physically ready he is," Martin told Sasa Ozmo. "He probably doesn't quite feel perfect but he is getting there.
"He is playing spectacularly this season, and he also got the experience of winning here.
"Novak and Rafa are the biggest challenge because they know how to win a title here (at Wimbledon). They've done it before."
One of Nadal's coaches, Francisco Roig, was asked about the current situation with Nadal's foot by the Spanish press following the fourth-round win over Botic van de Zandschulp and he said things were starting to look much more positive.
"No news, good news," Roig told Marca about the foot injury. "We don't talk about it, but it's good because we have been able to train a lot these weeks.
"There have been days in which we have played almost four hours."
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