14-time Grand Slam champion Rafael Nadal suffered a disappointing fourth round exit at the hands of Frenchman Lucas Pouille in a five-set epic that required a final set tiebreak to decide the contest at the US Open.

It's the first time since 2004 that Nadal hasn't reached a Grand Slam quarterfinal. Nonetheless, the Spaniard is representing Spain in the Davis Cup this weekend as they attempt to return the World Group Stage of the Davis Cup.

The former world number one is not surprised by Stan Wawrinka's US Open victory, coming back from a set down to halt Novak Djokovic's chances of claiming his 13th Grand Slam singles title in four sets.

Nadal praises Wawrinka

Wawrinka stunned Nadal in four sets to win his first Grand Slam single title at the Australian Open in 2014. Interestingly, all three of Wawrinka's Slam triumphs have been won in four sets and against the world number one tennis player.

"Stan is a player that over the last couple of years has been playing great tennis. When he is playing well he is able to play very well against all opponents."

The current world number four will be hoping to qualify for the ATP World Tour finals, and he topped his group last year recording victories over Wawrinka, Andy Murray and David Ferrer, ultimately losing to eventual winner Novak Djokovic in the semifinals.

The Spaniard speaks about India

Nadal spoke about Spain's opponents, India, and noted that they should not be taken lightly, "We lost a couple of confrontations where we believed we were the favourites and we were in a good position to win, so maximum respect for all opponents, for India."

The Spaniard will be participating in his third Davis Cup tie in four years, and he spoke about balancing Davis Cup commitments along with a rigorous schedule on tour.
 

Wawrinka and Nadal holding their respective trophies following their clash in the final of the Australian Open in 2014 (Photo by Mark Kolbe / Getty Images)
Wawrinka and Nadal holding their respective trophies following their clash in the final of the Australian Open in 2014 (Photo by Mark Kolbe / Getty Images)

"Everyone has his commitments and playing Davis Cup also depends on whether you're healthy, which is the most important thing. For me, it's always special to play for my country."

Although, this is the second consecutive year that Nadal is slamless, he claimed his second Olympic gold medal in Rio by winning the doubles with his good friend and reigning French Open doubles champion Marc Lopez.

The former world number one suffered a wrist injury in May that ruled him out of action for two and a half months just when it seemed that the Spaniard was finally getting back on track.

Nadal has been inconsistent over the last couple of years but he remains as hungry as ever to do well in the sport that he loves.