London: World number one Rafael Nadal fears he could be the victim of another Wimbledon giant-killing this year.
Nadal continues to trounce all challengers on his favourite claycourts at the French Open, where he was crowned champion for an incredible ninth time earlier this month.
But after reaching the All England Club final five times between 2006 and 2011, the two-time Wimbledon champion has endured a miserable time on grass of late.
Nadal endured a shock loss in the Wimbledon second round against Lukas Rosol in 2012 and was embarrassed by Belgium`s Steve Darcis in the first round last year.
The 28-year-old followed that by suffering his third successive loss on grass when he crashed out of the Wimbledon warm-up in Halle against Dustin Brown earlier this month.
Roger Federer, the seven-time Wimbledon champion, had said earlier on Saturday that Nadal might be vulnerable in the early rounds and the second seeded Spaniard agrees that the transition from the clay to grass with little preparation time makes him nervous of potential problems lying in wait next week.
"I`ve said before this is really the most dangerous tournament of the year," Nadal told reporters on Saturday.
"When I arrive at Roland Garros I already played for one month on clay. I played a lot of matches. So more or less I can imagine how I am going to play. US Open is the same.
"Here, especially the beginning of the tournament, the courts are a little bit faster. The feeling on court is a little bit strange for everybody. Especially the top players who have more pressure.
"Then the match is decided in a few balls, so you need to convert the small opportunities that you have.
"If you are able to win a few matches, you have the feeling you are in the tournament and everything becomes a little bit more."
With Rosol lurking as a potential second round opponent this year, and big-serving Ivo Karlovic another tricky challenger in the third round, Nadal, who starts against Slovakia`s Martin Klizan, knows he has to navigate the first week successfully before he will start to believe he can win the tournament.
He has often arrived at Wimbledon struggling with knee and back problems, with the gruelling claycourt campaign aggravating his long-standing injury issues.
But this year the 14-time Grand Slam winner says he feels in better shape heading into the tournament in south-west London.
"I am feeling better this year than last couple years, seriously. Personally I feel that I am doing the things better," he said.
"I am able to move myself more freely now. I`m not scared about my knee. That`s the most important thing for me.
"But then is true that for the last couple of years I didn`t play lot of matches on grass.
"I am confident that I can do it again. Not talking about to win, talking about play better than what I did last couple of years on grass."
Nadal has traditionally returned home to Manacor in Mallorca to relax with his friends and family after Roland Garros, and once again he followed that routine to give him time to recover from his French Open heroics.
"I came back home. I didn`t practice tennis for a while. I went a few days with the family, with friends," he added.
"I was able to go for a party on Saturday with my friends. I was able to go to the beach few days in Mallorca.
"I needed a few days off for my back after a lot of stress for my back in Roland Garros.
"I really tried hard on Halle, even though I know I was not able to have good success there. But a few days of practice helped me remember a little bit how to play here on grass."