Madrid Open advisor Ion Tiriac has apologised for the state of the under-fire blue courts, admitting they are "slippery".
The new blue claycourts have been heavily criticised by Rafael Nadal - who suffered a shock defeat to Fernando Verdasco - and Novak Djokovic because they lack sufficient grip. As a result, both men have threatened to skip next year's event.
"The court is slippery and I apologise," said Tiriac, the man behind the blue clay idea, on Friday. "We wanted to make sure that we had no player injuries, no ankle problems.
"As a result, the court experts rolled the base with too much pressure. When the blue sand was put on top it was unable to meld with the base, creating the slippage."
But Tiriac insists the colour will stay as a year-round feature at the Caja Magica and he believes it will eventually be as comfortable to play on as traditional red clay.
"It's a pity," Tiriac said of the boycott threat. "I would be very sad if they did not play.
"The players are right when they say it is too slippery. We are working daily to fix that and things are getting better. There are still three days to go this week."
