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A two-year trial of Video Assistant Referee technology was approved by the International Football Association Board in 2016

Video Assistant Referee (VAR) technology will be used in both legs of the Carabao Cup semi-final between Chelsea and Arsenal.

It will also be used in the final next month but not in the semi between Manchester City and Bristol City.

Monday's FA Cup third-round tie between Brighton and Crystal Palace will be the first time the technology is used in a competitive club match in England.

The International Football Association Board agreed a two-year trial in 2016.

VAR can be used in four "match-changing" situations - goals, penalty/no penalty decisions, straight red cards and cases of mistaken identity by the referee.

Referees' chief Mike Riley said the technology will never be "100% perfect".

"It's going to take us time," he said. "You're actually asking a generation of referees to relearn or learn new processes and skills.

"It will never be 100% because it's so subjective on certain things and we're asking the clear and obvious question.

"We don't want errors. If through this we make that 4% [of incorrect decisions made by select referees] 2%, we've benefited the game."

He added: "There will still be debate; there will still be interest. We are not sanitising the game through VAR."

VAR was first deployed in an official match in the UK for England's goalless friendly draw against Germany in November 2017, although it was not called on by the referee.

Since being used in the Club World Cup in December 2016, VAR has also been deployed in the 2017 Confederations Cup and domestic competitions in Germany and Italy.

Chelsea host Arsenal in the first leg of the Carabao Cup semi-final on Wednesday, before the return leg on 24 January.

The final is at Wembley on 25 February.