Roger Federer can be forgiven for hedging his bet just a bit.

Tennis.com reported that the world's No. 2-ranked Federer still believes rival and fourth-ranked Rafael Nadal should not be discounted at the French Open next month.

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Nadal has won the French Open five straight years and nine of the last 10. But he has just one since winning the 2014 French Open - an ATP 250 event in Buenos Aires, according to tennis.com

No. 1 Novak Djokovic has won eight events since last year's French Open, including the 2014 Wimbledon and the 2015 Australian Open.

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So when the 17-time Grand Slam champion Federer gives his opinion on who he believes is the favorite at Roland Garros, he answers like a 17-time Grand Slam champion.

"At the French Open, Rafa for me is still the favorite alongside Djokovic who has been playing so well," said Federer, according to tennis.com. "Even though (Nadal's) form is not as good as in previous years, I still believe when the French Open rolls around he is going to be very difficult to beat."

Federer owns the one title that Nadal didn't win at Roland Garros in the last decade - in 2009.

An injury-plagued 2014 left Nadal unprepared to start 2015. But while his health has returned, Nadal's confidence has suffered, which has contributed to his lack of match-readiness. He has talked about trying to regain his confidence throughout the first half of the season.

Nadal was beaming after a 6-3, 6-3 loss to Djokovic in the semifinals of the Monte-Carlo Rolex Masters in mid-April, saying he felt his game was on track to get him back into form by the French Open.

But then Nadal lost in the third round of the Barcelona Open to Fabio Fognini in straight sets, throwing Nadal's recovery into a tailspin.

Federer has had a front-row seat to Nadal's dominance, losing four French Open finals (2006, 2007, 2008, 2011) to the Spaniard. So it's easy to see why he has a soft spot for Rafa at Roland Garros.

But the results in 2015 make it hard to bet against Djokovic.