Chelsea manager Antonio Conte and Arsenal counterpart Arsene Wenger have questioned aspects of the video assistant referee system after it was used during their goalless English League Cup draw.
The system reviewed two penalty decisions, one for each side, during the first leg of the semi-final clash at Stamford Bridge, with referee Martin Atkinson and VAR assistant Neil Swarbrick agreeing neither incident warranted a spot-kick.
Italian Conte said he was "positive" on the technology but frustrated by what he considered insufficient stoppage time at the end of the second half to accommodate for delays caused by the review and injuries.
"In the second half the doctor went onto the pitch twice and the referee stopped for VAR, so you have to give more minutes," he said.
Wenger questioned the delay between incident and review after the second penalty appeal following a Danny Welbeck tackle on Cesc Fabregas in the box was rejected by Atkinson but then reviewed. "It looks a bit strange to go on for two minutes ... and then to come back," he said.
Still, Conte backs the review system, saying: "When there is a doubt during the game the referee can check and see the situation again and make the best decision. In this way for sure the mistakes are less."