World No. 1 Rafael Nadal does not expect to sweep the clay court season, like he did in 2010.

"What I did last year, winning Monte Carlo, Rome, Madrid and Roland Garros, was historic,” said Nadal in Monte Carlo. "I don’t think that I can do it this year. It didn’t happen in 50 or 60 years. So I guess I can’t do the same two times in a row."

The Spaniard also expects the battle for the year-end No. 1 spot to be heated. "Of course, it’s very open," he said. "Roger [Federer] has a chance, Djokovic as well. I have some advantage in the rankings for now, but you never know how things will turn out. Novak is playing extremely well. He’s got a huge potential and he’s on a winning streak, which gives him a lot of confidence. So we’ll see at the end of the year who will be No. 1."

Nadal is chasing a record seventh consecutive title at Monte Carlo. He’ll face Jarkko Nieminen in his opening match.—Matthew Cronin