UEFA plans to introduce video assistant referees (VAR) to the Champions League next season.
VAR was brought in for several domestic competitions across Europe last term and was then in use at the World Cup, but UEFA held off on its implementation in its flagship tournament for the current campaign.
However, president Aleksander Ceferin has suggested that, while there are no guarantees, UEFA aims to bring VAR in for the 2019-20 season.
"VAR is not completely clear for now but we also know there is no way back any more," he said.
"It is much more problematic than it looks. We really have a huge territory. The plan is to do it for next season but let's see what happens. I don't want to predict anything 100 per cent."
The suggestion is that VAR would be introduced for the final qualifying round of next year's Champions League, as well as the UEFA Super Cup.