Phil Parkinson criticised VAR in Wrexham's first encounter with the system during the dramatic 4-2 loss to Chelsea in the fifth round of the FA Cup.
Wrexham had two decisions go against them after being reviewed by VAR with George Dobson's initial yellow card being upgraded to a red in the 93rd minute and Lewis Brunt's equaliser to make it 3-3 ruled out for a correct offside call in extra-time.
The hosts had previously taken the lead on two occasions at the Racecourse Ground but quickly lost grasp of the fixture after being reduced to 10 men, with Alejandro Garnacho and Joao Pedro scoring in the extra period to seal an unconvincing win for Chelsea.
VAR is not used in the Championship and was not used in the previous rounds of the FA Cup.
"It's such a shame that our first taste of VAR has gone this way because it will be the talking point," Parkinson told TNT Sports.
"I thought VAR was meant to be for clear and obvious decisions. Dobbo's gone in with force. The referee is in a good position to see it. He has scraped his shin.
"It's caught him low down. I thought he could've easily kept that as a yellow. In my opinion, I don't think the VAR should've intervened.
"It was a tight call and if that's the case you should leave it with the onfield decision."
Chelsea boss Liam Rosenior agreed with the decision to send Dobson off after he dived in on Garnacho and caught the winger on the knee.
"It's dangerous," he said to TNT Sports.
"I don't ever want to see a player be shown a red card. For me, they are the challenges you don't want to see."
"They're both correct decisions from me. I know it's frustrating. Any challenge that's dangerous is a dangerous challenge, and if you're offside, you're offside.
"It doesn't matter how small the margins are. We needed elements of luck today because Wrexham were that good in terms of their performance."
