By Brian Homewood
AGADIR, Morocco, Dec 17 (Reuters) - The vanishing spray used by referees to stop defensive walls creeping forward at free kicks will only work if they measure the distance correctly, Guangzhou Evergrande coach Marcello Lippi said on Tuesday.
The former Italy and Juventus coach complained that the referee had made his team's defensive wall move back "15 metres" at Bayern Munich free kicks during Tuesday's Club World Cup semi-final, which the European champions won 3-0.
The proper distance should be a little over nine metres (9.15m/10 yards).
"It's an intelligent idea, but for it to work, the referee has to measure the right distance between the ball and the wall," said Lippi. "There were two Bayern free kicks where he made our wall retreat 15 metres."
The spray, being deployed for the first time at a senior FIFA tournament, was developed in Brazil and Argentina, where it has been used for several years.
Referees carry a small canister and spray a line on the pitch to mark the place the defensive wall should stand after pacing the nine metres. Its proponents say it prevents arguments over where the wall should be.
"You don't waste time, it's there for 15 seconds and the line is gone," said Bayern Munich coach Pep Guardiola. "When there's a free kick, it's good to know where the wall should stand, to keep the right distance and I hope it continues." (Editing by Peter Rutherford)