Brazil [Images] striker Ronaldo [Images] joined the controversy over new technology in football on Thursday when he criticised ear-pieces, artificial pitches and so-called intelligent balls.

Vanderlei Luxemburgo, Ronaldo's coach at Real Madrid [Images], recently tested a system which allowed him to pass instructions on a walkie-talkie to his captain Raul during the match.

Raul received the instructions via an earpiece held in place by tape as Luxemburgo repeated an experiment he had tried to implement at Brazilian club Corinthians before it was banned by local authorities.

Ronaldo did not appear keen at having either Luxemburgo or Brazil coach Carlos Alberto Parreira speaking to him during matches.

"I don't see any advantage in this," Ronaldo told Reuters in an interview at Brazil's training camp.

"Apart from being uncomfortable in the ear, it doesn't really alter anything. On the pitch, the most important thing, apart from being well-positioned tactically, is to carry out what you have done during the week in training.

"Usually, it's the quality of the players which decides the match, not having the coach telling you whether it's the right moment to take on the defender or not."

Ronaldo was equally unenthusiastic about the innovations tested by FIFA at the world under-17 championship in Peru.

SYNTHETIC PITCHES

The competition was played on synthetic pitches and each match ball contained a chip indicating to the referee whether or not it had entirely crossed the line on entering the goal.

The chips send a signal to the referee's watch via sensors around the pitch.

"I think a much easier and more viable solution for this type of situation would be to have more referees," said Ronaldo.

"In basketball, which has fewer players on the court, you have several controlling the game while we just have two linesmen and the referee.

"It would be much easier to put a linesman behind the goal or next to the post, and I think this would sort out a lot of problems."

He said he preferred more assistants on the touchline rather than on the field.

"I don't think you need anyone else on the pitch itself because the referee is always in good shape, he is always close to the game. But he needs more assistants to help him, to spot things he can't see."

When it came to artificial pitches, Ronaldo spoke from personal experience.

"In my case, I'm not very keen on the artificial pitch," he said. "I trained a lot on artificial pitches in Italy [Images], during their winter for example, and the impact is much greater on the joints.

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