Rafael Nadal's loss of confidence soon could result in the loss of the world's No. 1 ranking.

The top-ranked player again suffered a puzzling defeat, falling to someone named Nicolas Almagro 2-6, 7-6 (5), 6-4 in the quarterfinals of the Barcelona Open on Friday. The loss was Nadal's second quarterfinals loss on his preferred surface.

He lost last week to David Ferrer in the Monte Carlo Rolex Masters, but this defeat happened on the Spaniard's home soil.

According to USA TODAY Sports' For the Win, Nadal had a 41-match winning streak snapped in Barcelona. The 27-year-old Nadal hadn't lost there since he was 15 years old. In the span of eight days, For the Win reported, Nadal lost as many clay-court matches as he has in any single year since 2004.

The loss put Nadal in danger of losing the No. 1 ranking he reclaimed from Novak Djokovic last year. For the Win states that Djokovic can surpass Nadal in Madrid, a primer for the French Open at the end of May.

Nadal already has said publicly that his confidence suffered a hit during his Australian Open finals loss to Stan Wawrinka, in which he was also dealing with an ailing back.

"I don't have to lie to anybody," Nadal said after his loss to Ferrer in Monte Carlo. "After what happened in Australia it was little bit harder for me to find again the intensity, the confidence, the inside power that I always have."

After the match against Almagro, Nadal was philosophical about the surprising loss.

"I felt I did a lot of things well to win, but at the end, [there] remained a little bit [missing]," Nadal said, as tennis.si.com reported. "Just accept the situation and keep fighting."

"For two sets I was playing better than him, much more chances than him. I was in advantage [in the third set], in control, and I missed a lot of opportunities during the match. And playing against a good opponent like him, the normal thing is lose in the end and that's what happened."

Do you think Rafael Nadal can gain back his confidence in time for the French Open that begins on May 25? Comment below or tell us @SportsWN.