Rafael Nadal has reportedly threatened to pull out of next year's Madrid Open if the clay courts remain blue following his shock defeat to Fernando Verdasco.
The Spaniard went down in three sets against the world number 19 on Thursday afternoon to see him exit in the third round.
The world number two described the blue courts as difficult on Wednesday.
"I was not good enough to adapt my game to this court. If things continue like this, it will be very sad," he told reporters.
"Next year this will be one less event for my calendar."
Novak Djokovic is another player to have criticised the surface in the past few days.
