Roger Federer may have declared himself ready to win a Grand Slam title again, but even he is realistic about the prospects of an elusive 18th title arriving at Roland Garros at the start of June. The French Open has represented the toughest of the four Majors for Federer, having seen his hopes ended on five separate occasions by the man regarded as the greatest clay-court player in history, Rafael Nadal.

While Federer did land the title in Paris to complete a career Grand Slam in 2009, the French Open and seven matches on the grueling clay surface unquestionably represent the most difficult assignment for the 34-year-old.

And that task is even greater this year. Federer has played just one tournament since undergoing knee surgery days after his Australian Open final defeat to Novak Djokovic at the end of January. That appearance came at the Masters 1000 event in Monte Carlo three weeks ago, when the Swiss suffered a quarterfinal exit to Jo-Wilfried Tsonga.

Federer is not currently scheduled to play another event before the French Open begins on May 22, although he does have the option of making late entires into the Masters 1000 events in Madrid and Rome. However, he also has to consider the fact that he has a hectic summer ahead, including Wimbledon, the U.S. Open and the Olympics, all events where Federer will consider he has a better chance of winning than Roland Garros.

Speaking to Spanish sports newspaper Marca last week, Federer did not rule out a French Open run, but was far from demonstrative when discussing his prospects.

"I don't think I have zero chance to lift the title at Roland Garros,” he said. “I think if the draw is in my favor, if I'm playing well, I'll have my chances.”

Federer has not made it beyond the quarterfinals for past there years in Paris, and indication of the extra difficulty the clay-court surface poses at this stage of his career. His impressive Grand Slam results over the past year—reaching the final at Wimbledon and the U.S. Open and the semifinals at at the Australian Open—have come thanks to a renewed commitment to attacking tennis. It is a strategy than earns far more reward on faster surfaces, rather than the slower clay-courts.

Last year in Paris, Federer lost to eventual champion Stan Wawrinka, who is just one of the men likely to stand between him and the title at Roland Garros. At the top of the list is world No. 1 Novak Djokovic, who has suffered just one defeat in a completed match in 2016 and has beaten Federer in the last three Grand Slams. But there is now a renewed threat set to come from nine-time champion Nadal.

After a desperately disappointing 2015 and a poor start to 2016, Nadal has shown signs of returning to close to his best in taking the titles in Monte Carlo and Barcelona. And, while Djokovic, still chasing a first title at the French Open, is widely seen as the favorite, Federer insists it would be foolhardy to write off Nadal.

"He's the player to beat. Novak has never won in Paris. He could be now the favorite, but Nadal is Nadal.”