Fifa's plans to bring video replays into football have been plunged into doubt after Real Madrid stars criticised its use during their 2-0 Club World Cup semi-final win over Mexico's Club America.
Cristiano Ronaldo and Luka Modric blasted the technology currently being trialled by Fifa after the former's injury time goal took nearly a minute to be confirmed while confusion reigned on the pitch.
Ronaldo's celebrations were cut short when Paraguayan referee Enrique Caceres signalled he was checking with a video assistant referee (VAR) whether the goal should stand.
After initially appearing to wave play on, Caceres then awarded the goal without checking with the replay footage available to him on the side of the pitch — an optional but not compulsory measure available to referees.
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"It is a new system, even a new event, and I do not like it very much," said former Spurs midfielder Modric.
"That is because I think it can cause a kind of confusion and we have not had it explained to us in too much detail.
"I do not like football with this kind of a system being introduced. I want to focus on the match and play my own football, so my first impression was it's not a good system."
Ronaldo was more direct, saying "the television doesn't work" as he walked off the pitch.
In the other semi-final between Japan's Kashima Antlers and Colombians Atletico Nacional, play was pulled back to award a penalty after Viktor Kassai missed an off-the-ball foul, but play was held up for three minutes while he consulted pitch-side videos.
Fifa will have to consider criticism from some of the world's biggest players when consulting with the International Football Association Board (IFAB) about whether to roll out trials internationally.
Writing in City A.M., former Premier League referee Howard Webb has warned fans that video replay technology requires serious testing and is unlikely to completely rid incorrect decisions from football.
"Even with the benefit of video we will still get decisions which will split people 50-50 – the technology won’t be a panacea," said Webb.
Real Madrid manager Zinedine Zidane, echoed a similar sentiment after his team's progression to Sunday's final in Yokohama.
"We need to get used to it," he said. "If that is Fifa's policy it is up to us to get used to it. My personal opinion is that it could cause some confusion but Fifa's technical group will make a good decision.
"It could be better as everything could become clearer."