Blue clay used at ATP 2013 has been banned by the World Tour for all 2013 Madrid Masters events . After losing to fellow Serb Janko Tipsarevic in straight sets on the surface last month , Djokovic said he wanted to `` forget this week '' and move on to `` real '' clay courts . ' Rafael Nadal and Novak Djokovic voiced disapproval after losing matches on surface . Surface pioneered by former Romanian tennis star and businessman Rafael Nadal .
Blue clay used at ATP 2013 has been banned by the World Tour for all 2013 Madrid Masters events . Rafael Nadal and Novak Djokovic voiced disapproval after losing matches on surface . Surface pioneered by former Romanian tennis star and businessman Rafael Nadal .