Premier League officials are facing their most critical test to prove to clubs that video assistant refereeing is fit for purpose as they stage their first "multi-match" top-flight trial later this month.
VAR testing will take place simultaneously at all the 3pm kick-offs on September 15 when league chiefs aim to prove they have the technological capacity to deal with the workload posed on a busy Saturday schedule.
The games will be treated as a normal VAR game, but the assistants in the VAR hub will not have any communication with the on-field referee.
Testing has been stepped up in recent weeks with particular focus on ensuring the nerve centre at Stockley Park, near Heathrow airport, can cope when multiple incidents take place at once.
A Premier League source said referees have been encouraged by the use of the technology at three recent EFL Cup matches at Brighton, Fulham and Leicester.
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Former elite referees Mike Dean and Neil Swarbrick are in overall charge of the testing. Swarbrick said recently that "it's disappointing" that clubs had not already embraced VAR in the Premier League.
Clubs voted in April to wait until officials had more experience, and to see how it was received in the World Cup. This season VAR is being used at around 60 cup matches ahead of its intended full roll out in the Premier League next season.
The trials "will allow the officials to get better and quicker at using it, which is what the clubs wanted," Swarbrick previously said.
Uefa is also likely to use VAR in the Champions League next season. Uefa president Aleksander Ceferin said last week: "For me, VAR is not completely clear, but we also know that there's no way back anymore. Technology will come sooner or later. The plan for now is to use it from the next season.
"This is the plan but of course I am not an expert. But it is not so easy because we have to choose the provider, it's not easy to organise a competition across the continent with all the referees, so we have some issues."