Southampton manager Mark Hughes has been a strong advocate of the video assistant referee but the Welshman felt the technology had been used badly in Tuesday's Carabao Cup fourth-round defeat to Leicester City.
Southampton had a late Steven Davis effort disallowed after VAR had determined there was a handball incident in the buildup to the goal. The match ended 0-0 before Leicester prevailed 6-5 on penalties.
"We've had a perfectly good goal chalked off by VAR ... the referee, in fairness to him, actually said if it wasn't for VAR, he would have given it because it happened so quickly," Hughes told Sky Sports.
Earlier this month, Southampton striker Charlie Austin made a passionate plea for the technology to be introduced in the Premier League after having a goal disallowed in the 1-1 draw with Watford.
Top-flight clubs have agreed in principle to allow the system to be used from the start of next season.
"In recent weeks, we have demanded it be introduced, so we can't complain too much," Hughes added.
"But if the guys behind the screen looking at a situation slow it down to nth-degree, then something that's not deliberate in real time then looks deliberate when it is not.
"From our point of view, it's a valid goal that should have stood and we should have won the tie. I suppose the more the system is used, the better it'll get."
Southampton, who are 18th, return to action with a Premier League encounter at home to Manchester United on Saturday.