Nadal is taking a week off before heading to Paris

The 20-year-old has not gone beyond the semi-finals in any tournament since reaching the Wimbledon final in July.

"The Rome Masters and Wimbledon were my best two tournaments this season and since then I've been feeling tired," said the world number two.

"I had a lot of matches in the first half of the season and my muscles were very tired. Mentally, too, it was a big effort. But I'm playing better now."

Nadal is currently taking a week off before he heads to Paris for the Masters Series event, starting on 30 October.

"I'm going to Paris to do well because it's one of the most important events of the season," Nadal said.

"I feel much better now than a couple of months ago."