FIFA: Adidas 'smart ball' not ready for World Cup
Tracking technology behind chip-implanted soccer balls, designed to rule out bad goal line calls, needs more testing.
"The technology is not yet ready," FIFA general secretary Urs Linsi said.
Designed to rule out mistakes on goal line decisions, the technology was first tested at the Under-17 World Championship in Lima, Peru, in September.
"We knew of this decision in advance of course, so we are not surprised nor are we disappointed," Adidas spokesman Thomas van Schaik said.
The official tournament ball will be unveiled during the draw ceremony on Friday evening.
It contains a microchip, about 1.5 centimeters, which sends out a radio signal when the ball crosses the touchline, as if it had touched an electric fence.
That signal is relayed by up to 12 antennae positioned in the corners of the pitch to a computer, which then sends a message to a watch worn on the referee's wrist in less than one second.
Adidas is "still developing the tracking system, and when we are convinced it is 100 percent bulletproof, 100 percent perfect, then that will be the time for it to be used," Schaik said.