World number one Novak Djokovic has criticised the new blue clay court surface at the Madrid Open this week.
The Serb struggled his way to victory over Daniel Gimeno-Traver this afternoon and slammed the new surface after the encounter.
"To me that's not tennis. Either I come out with football shoes or I invite Chuck Norris to advise me how to play on this court," said the 24-year-old.
His criticism follows doubts from home favourite Rafael Nadal about the clay installed by tournament consultant Ion Tiriac.
"I hit five balls throughout the whole match. With everything else, I was just trying to keep the ball in the court," Djokovic added.
"When you slide on the red clay you have a feeling you can stop and recover from that step. But here, whatever you do, you are always slipping.
"Not a single player - not woman, not man - I didn't hear anyone say 'I like blue clay'."
Djokovic, the defending champion in the Spanish capital, will now face either Stanislas Wawrinka or Jurgen Melzer in round three.