Arsenal take on Manchester City at Wembley in the Carabao Cup final the afternoon.
And they will do so with the addition of VAR to help Craig Pawson and his team.
The system is being trialled in English football and has thrown up some hiccups with wonky lines and controversy over how long decisions take to be reached.
So what is it?
What is VAR?
The Video Assistant Referee system is designed to help match officials get more decisions right.
It is supposed to come into action when officials have made a ‘clear and obvious’ error in four areas: goals, straight red cards, penalties and mistaken identity.
How does VAR work?
Referees’ chief Mike Riley explained: “The biggest challenge is understanding that this isn’t about making the game 100 per cent perfect.
“It is to address and reduce clear and obvious errors. We don’t want this to sanitise the game or for it to be stopping every two minutes while everyone stands around and gets frustrated.
“The select group of referees get 96 per cent of decisions right, so four per cent wrong.
“We don’t want errors in the game and if this improves it by two per cent then the game has improved. That would be two per cent less decisions for people to get agitated about.
“That is good for the game — as long as we don’t increase interference, because we want to the game to flow.”
Why are they using it in the Carabao Cup final?
VAR has been trialled in Cup games where the stadium has the facility for it to work.
And today messages will be shown on the big screens so supporters are aware when reviews are being made – although incidents will not be replayed.
Neil Swarbrick will be the video assistant referee charged with advising Pawson whether an incident needs to be looked at further.
Shaun Harvey told The Times: “This cup final will be the biggest game for VAR in England so far.
“If there is a notice on the big screen explaining why there is a delay to the game then we hope that will improve communication to fans inside the stadium and on television.
“If everybody in the stadium knows what is going on then that’s part of the overall education of what VAR can achieve.”