Chelsea manager Maurizio Sarri was left frustrated after VAR granted Tottenham a decisive penalty in their 1-0 loss in the Carabao Cup on Tuesday night.
On a largely frustrating evening which saw both N'Golo Kante and Callum Hudson-Odoi strike the woodwork, Harry Kane's clinical first half spot-kick separated the sides - but not without controversy leading up to the game's only goal.
Despite initial replays from VAR showing the Tottenham goal-scorer in line with the Blues' defence, another version on Chelsea's club camera footage appeared to show Kane in an off-side position - before being upended by goalkeeper Kepa Arrizabalaga.
Speaking post match to reporters via skysports.com, Sarri criticised the decision that left his Chelsea side needing to overturn a deficit in a fortnight when the second leg of the semi-final takes place:
"I saw the video from our camera a few minutes ago, it was offside. Our camera was in line with Kane, and it was offside, but it's not important.
"We deserved more because in this match we played better than the opponents. We were in control of the match and defended well against a team dangerous in the offensive phase, so we deserved more."
In November 2018, Premier League clubs agreed in principle to allow the introduction of VAR in the forthcoming 2019/20 league season.
Having experienced VAR with Napoli in Serie A last season, Sarri suggested the inexperience of English officials was to blame.
He added via Chelsea's official website:
"In Italy there is VAR and in the first period it was a disaster, it was really very difficult for the referee to get used to the system and I think here the referees are not ready to use it in the right way.
"It is strange in the Premier League there is not this system and then in the Carabao Cup there is suddenly the system. At the moment I think the English referees aren't able to use the system."