Istanbul: Switzerland's 17-times Grand Slam winner Roger Federer on Monday said he still believed Rafael Nadal was the favourite to win the French Open next month despite the Spanish star's troubled start to the clay court season.


Roger Federer and Rafael Nadal 

Federer, who took his sole French Open title in 2009, this week is refining his own clay court game at the Istanbul Open, the first ATP World Tour event to be held in Turkey and the first time that Federer has visited the country.