Two-time champion Rafael Nadal has admitted that he may never be able to produce his best at Wimbledon again following his shock defeat to Dustin Brown in the second round.

Injuries and poor form in the last two years have seen the Spaniard drop down to 10th in the world rankings, and he suffered more disappointment at SW19 on Wednesday as qualifier Brown clinched the win in four sets.

"I don't know if I will be back to the level of 2008 or 2010," the 29-year-old told reporters. "My motivation is try to be back to that level. But I've got to keep working.

"If I don't make that happen then I've played five finals and taken the trophy back home two times, so that's not bad.

"It's not the end. It is a sad moment for me but life continues. My career, too."

Nadal has lost to a player ranked outside the world's top 100 in each of his last four appearances at Wimbledon.