Nadal says will be 'very tough' to reclaim World No.1 ranking

World No.2 Rafael Nadal has said that it will be very tough to seize Serbian player Novak Djokovic's crown as the top ranked men's tennis player, while giving respect to his 'unbelievable' opponent at the China Open on Sunday.

According to Sport24, the world number two can unseat Djokovic from the top spot with a good performance in Beijing, but the Serb will go into the tournament with confidence he can retain the title he won last year.

Djokovic is unbeaten in three visits to the China Open, following up wins in 2009 and 2010 with victory over Jo-Wilfried Tsonga in last year's final, the report said.

Spaniard Nadal has been in fine form since coming back from injury earlier this year, and defeated Djokovic at this month's US Open final, the report added.

However, the 2004 champion in Beijing says overcoming Djokovic is no easy feat, the report further said.

Nadal said that he knew that his opponent was unbelievable and was not able to lose many matches during the whole season, adding that it will be very tough to become number one.

The Spaniard still believes that if he plays the same way he has during the last couple of months, he could have his chances here or in the next few weeks.

Djokovic is the top seed in Beijing, ahead of Nadal, according to the report.

The reigning champion will play Czech Lukas Rosol, who is ranked 46th in the world, in his opening game, while Nadal will face a qualifier, the report mentioned.