Courting controversy as blue is now the new red

'Smurf clay' may be popular with organisers – but not with the players

From his breakthrough years when he dressed in sleeveless shirts and "pirate" shorts to his recent campaigning for a better deal for journeyman players, Rafael Nadal has been anything but a traditionalist. Even as he approaches what counts for middle age in tennis – he will be 26 next month – the world No 2 insists that he loves innovation and improvement.

This time, however, Nadal believes his sport has gone too far. The Spaniard has earned his reputation as the king of clay through his exploits on courts covered by crushed red brick, but the playing surface at this week's clay-court Madrid Masters is Chelsea blue rather than Liverpool red. Tournament organisers say it will be easier for players and spectators to see the ball; Nadal says it is an unnecessary promotional stunt which threatens to "destabilise" his preparations for the French Open, which begins in three weeks' time.

The man behind the blue revolution is the Romanian businessman, Ion Tiriac, one of the great entrepreneurs of tennis. Ilie Nastase's one-time doubles partner, who also employs glamorous models as ball-girls in Madrid, has had a blue bee in his bonnet for years. He first introduced blue courts at his indoor event in Stuttgart, a lead followed by a host of tournaments, including the Australian and US Opens.

Nadal, however, is adamant that the change in Madrid is not for the better. "You are in the middle of the clay-court season and the clay here in Europe is red," he said. "Madrid is a big enough tournament not to need this promotion. The tournament is one of the best of the world. The history of the clay-court season was on red. It wasn't on blue."

The court builders say the manufacturing process for blue clay is very similar to that used for red clay and that the materials – apart from the blue dye – are identical. While the cynics note that blue is the colour associated with the tournament's main sponsor, others point out that other sports have made similar decisions. The last two world athletics championships have been held on blue tracks, while this summer's Olympic hockey tournament will be the first to be played on a blue pitch.

Novak Djokovic, the world No 1 and defending champion, said after his first practice session in Madrid last week that he felt the bounce of the ball was low. Canada's Milos Raonic, who described the surface as "Smurf clay", agreed and also said the courts were slippery.

Nadal, who like most other players turned down the chance to use a practice court laid with blue clay at the venue last year, believes the change is particularly disruptive given that the conditions in Madrid were already different to other clay-court tournaments. The balls fly faster through the Spanish capital's thinner air (the city is 650 metres above sea level), making the conditions at next week's Rome Masters better preparation for the French Open.

While Andy Murray understands the reasons for the change – he said he had sometimes found it "very difficult to see the ball" in Madrid - most leading players agree with Nadal. Roger Federer believes it is "important to stay true to tradition", while Djokovic said it was wrong to stage a tournament on a surface on which players had never competed. "I've never played on blue clay," he said. "Rafa hasn't. Roger hasn't. We're going out there and we're going to play on it for the first time ever."

Nadal and Djokovic are particularly unhappy that the decision to approve the change was taken by the president of the Association of Tennis Professionals without the agreement of the players.

However, an ATP spokeswoman said: "We told the tournament we would be happy to consider it, providing they completed the necessary testing on the surface, which they did. The ATP granted this permission for one year with the understanding that it will be reviewed following the event, of course taking into account feedback from players. We believe it is a good thing that our tournaments are trying to be innovative."

The leading women are also playing in Madrid. Maria Sharapova diplomatically said the courts were "a little bit different" and "obviously what the tournament wants", while Venus Williams described them as "a real fashion statement".