Rafael Nadal has withdrawn from the World Tennis Tournament in Rotterdam to focus on his fitness.

The Spaniard has revealed that his doctors have advised him to rest up following his lengthy run at the Australian Open, which ended with a defeat to Roger Federer in the final.

"I am very sorry to announce I won't be able to play in Rotterdam next week. After last year's absence from some tournaments, I started this season well and made a significant effort during the Australian swing," he wrote on Twitter.

"It's because of this that my doctors have strongly advised me to take it easy and give enough rest to my body before competing again to avoid further injuries. I fully understand that the Dutch fans will be disappointed. I am very thankful to [tournament director] Richard [Krajicek] for the great support and understanding."

Krajicek has revealed that he has made attempts to final another top-ranked player to replace Nadal in the competition.