Rafael Nadal doubts Wimbledon future after Dustin Brown defeat

Rafael Nadal, who won Wimbledon in 2008 and 2010, was beaten by a qualifier for the first time at SW19

Rafael Nadal says he may not be able to rekindle his former Wimbledon glories after a shock second-round defeat by German qualifier Dustin Brown.

The 14-time Grand Slam winner, now the world number 10, lost 7-5 3-6 6-4 6-4 as his miserable run at SW19 continued.

The Spaniard, 29, has been beaten by players ranked outside the top 100 in each of his last four appearances.

"I don't know if I will be back to the level of 2008 or 2010," said the two-time men's champion.

"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."

Nadal is currently at his lowest ranking in almost a decade and was beaten in the quarter-finals at both the Australian Open and French Open this year.

However, he warmed up for Wimbledon by winning the fourth grass-court title of his career in Germany in June.

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

Nadal's disappointment at this year's exit was greater than his previous three eliminations, he said after the defeat.

The Spaniard suffered injury problems in the run-up to the 2012 and 2013 Championships when he was beaten by Lukas Rosol and Steve Darcis respectively.

Last year he lost against Australian Nick Kyrgios, 20, in the last 16.

"In 2012 and 2013, I know I was not ready to compete well," he said.

"This year I was ready to compete well and I was playing well before that tournament.

"I had the right preparation, all the things I thought were going to be fine to play a good Wimbledon."