Manchester United manager Jose Mourinho has suggested he is happy for English football to adopt the VAR system, but only if the on-field referee makes the final decision whether to use the technology or not.
Mourinho's side were involved in fresh controversy during their 2-0 FA Cup fifth round win over Huddersfield, after VAR official Neil Swarbrick overruled the linesman's decision to award a goal to Spanish midfielder Juan Mata.
The United ace's effort was subsequently ruled out for offside after the use of inconclusive pictures, though Mourinho offered a pensive response in regards to technology's impact on the game after the final whistle.
"It's an experimental period,'' Mourinho told BT Sport, via ESPN. "They have to get rid of the bad and make it perfect.
"It should be the referee's decision. Why? Because the referee wants to perform well. I don't think they're happy to make mistakes and if they have the VAR to help them make the right decision, I think the referees are probably happy with that.
"But if the VAR changes their good decisions for bad decisions, I think they're not happy with that. It was a bit frustrating because the moment I saw [referee] Kevin Friend touch his earpiece, I knew something was going to happen.
Controversy aside, the Red Devils boss was pleased with his side's performance, as they booked their place in the FA Cup Quarter-Finals for the eighth time in 11 seasons.
"We knew that it would be difficult" Mourinho told BBC's Match of the Day. "It was hard but we started really well. With that second goal in the second half I think we killed the game and from that moment we were in control.
"Good counter-attacks, twice attacking the space well. Twice cold in front of the keeper, good decisions, good shots, good goals, important goals from us."