Nadal's reign under threat

 For the first time in nearly a decade Rafael Nadal, the undisputed king of clay, will walk into Roland Garros facing legitimate claims to his French Open crown.

When he arrived in Paris a decade ago looking as though he had just bounded straight off a Mallorcan beach it heralded the start of an unprecedented era of dominance.

A record nine titles followed as left-hander Nadal buried many an ego under Parisian brick dust.

Approaching his 29th birthday though and with major questions about his form and confidence, talk of "end of eras" is not just the usual pre-tournament hyperbole.World number one Novak Djokovic has been supreme throughout this year and is the clear favourite to claim the only Grand Slam title to elude the Serb. And there are others circling too.

Briton Andy Murray, who learnt his craft on Spanish claycourts but had never won a title on the surface before back-to-back successes in Munich and Madrid this year, has thrust himself into contention.

Seventeen-times Grand Slam champion Roger Federer, for whom Nadal has been a recurring claycourt nightmare, will think a second French Open title is achievable, while Japan's Kei Nishikori, Tomas Berdych, Stanislas Wawrinka, David Ferrer and even home favourite Gael Monfils will have roles to play in what promises to be the most open men's title chase for years.

Defending champion Nadal will be seeded seventh, meaning a possible quarterfinal clash with Djokovic, Murray or Federer, so if he is to notch up a 15th Grand Slam title it would arguably be his greatest achievement to date.

The big question on everyone's lips is can he rediscover his mojo in the nick of time after a string of surprise losses. Twice former champion Jim Courier believes the five-set format should ensure Nadal avoids an unceremoniously early exit, but thinks the Spaniard is vulnerable.

"For the first time in many years Nadal will not be the favourite going into Roland Garros," the American said.

"That role is now firmly occupied by Novak Djokovic. Nadal is less vulnerable in Paris, given the best of five set format which allows him more time to problem solve than elsewhere but there are now guys in the locker room who see him as an opportunity rather than an immovable obstacle."

Djokovic, who beat Nadal easily in Monte Carlo this year and has won every Masters 1000 event he has entered, as well as the Australian Open, is oozing confidence. His dominance is reminiscent of 2011 when he won three quarters of a calendar-year Grand Slam, only missing out at the French Open when an inspired Federer beat him in the semifinal.

Super Serena lurks

Maria Sharapova has hit form at the perfect moment as she eyes a defence of her French Open crown but old nemesis Serena Williams is lurking in the Parisian shadows.Russian Sharapova, who once despised claycourt tennis but transformed herself into the 2012 and 2014 champion, arrives in the French capital fresh from winning the Italian Open in Rome.

Yet most observers make twice French Open champions Williams the favourite -- even if she has suffered niggling injuries of late and can be at her most beatable on the red dirt. Romania's Simona Halep, last year's runner-up, will be in the mix too but few would be surprised if Williams and Sharapova served up a repeat of the 2013 final.

"I think this would be a better surface for her to play Serena," Chris Evert, a commentator for ESPN during the French Open fortnight, said in the build-up to the tournament.

"I think that it (the clay) defuses Serena's power. I think (Sharapova) likes that few extra seconds that clay allows her to set up her shots. She feels confident, she feels happy on the clay."

Williams, 33, will be aiming for a 20th Grand Slam singles title to move four shy of Margaret Court's record, but was forced to withdraw in Rome with an elbow injury, having also suffered knee problems earlier in the year.

Her physical condition will be severely tested over the coming fortnight. The list of those waiting to take advantage if the world number one stumbles is not a long one, however.
Halep has the patience on clay, while Wimbledon champion Petra Kvitova has the power but not necessarily the craft to survive two weeks at Roland Garros.

Former world number one Victoria Azarenka, coming back to her best after injury, could be a dark horse for the title.