Madrid, Dec 23 (IANS): Spanish tennis star Rafael Nadal has said 2015 was "the only year" in his life when he felt anxious while playing, an unpleasant feeling that prevented him from thinking straight while he was on court.

Nadal said he is usually never anxious thinking about the possibility of failure but poor form coupled with several injury problems resulted in a dip in rankings and confidence, reports Efe.

"For the first time in my career I've encountered feelings of fear of failure, not the fear of losing, but the fear of not be able to play," Nadal said on Tuesday.

The 14-time Grand Slam winner explained that his performance was affected by mental aspects, enduring a disagreeable feeling in his mind that impacted on his style of play.

The year was Nadal's first season in his professional career without a major title, while pointing out that his victory in the 2008 Wimbledon final against Swiss maestro Roger Federer was the most exciting moment in his career.

Nadal is set to travel to Abu Dhabi at the end of December to play two matches and then will travel to Doha where he will participate in the 2016 Qatar Open.

Furthermore, the World No.5 will head to Melbourne to take part in the Australian Open, and then he is heading for Rio de Janeiro in Brazil to take part in the upcoming Olympics next August.