FIFA s head of refereeing Massimo Busacca says video review has not always looked good in tests at the Confederations Cup.
Busacca acknowledges many aspects should be improved including faster, clearer communication after slow reviews have confused players, coaches and fans.
Still, the former World Cup referee says he is positive about the new system being approved for use at next year s tournament in Russia.
Busacca insists the most important point at the two-week rehearsal tournament is that technology helped referees avoid major errors in 12 games so far.
FIFA research cites video replays helping referees overturn six game-changing decisions. Referees judgment in a further 29 major incidents was confirmed correct on review.
Busacca says FIFA must convince more member federations to help by using video review in their national competitions.
