Russia's Karen Khachanov said the absence of line judges made Wimbledon's courts seem too big and players feel lonely as criticism of the technology resurfaced following another error on Tuesday.
Wimbledon's immaculately-dressed line judges often brought a theatrical element to tennis with their voices, postures and interactions with players, but the All England Club replaced them this year with live Electronic Line Calling (ELC).
Powered by more than 450 cameras across 18 courts, the ELC system has received mixed reviews, coming under the spotlight on Sunday when a malfunction robbed Russian Anastasia Pavlyuchenkova of a point in her win over Briton Sonay Kartal.
Organisers blamed that on human error and said they had conducted a review of the system to avoid similar issues in the future.
In Khachanov's 6-3 6-4 1-6 7-6(4) quarterfinal defeat by Taylor Fritz on Tuesday, a point during the fourth set had to be replayed after an automated call of "fault" was heard when a shot landed in.
"To be honest, I'm more for line umpires. I don't know. You feel a little bit that the court is too big, (you're) too alone without line umpires," Khachanov told reporters.
"At the same time, electronic line calls have to be precise and no mistakes, but we have seen a couple. That's questionable why this is happening. Is just like an error of the machine or what's the reason?
"Today I think there were a few calls, very questionable if it's really touching the line or not. At the same time, during one point, the machine called it just out during the rally.
"Sometimes it's scary to let machines do what they want."
The All England Club said Tuesday's malfunction had occurred as the system incorrectly tracked one of Fritz's shots during a rally as if it was a serve when a ball kid crossed the line while he was serving.
"The player's service motion began while the BBG was still crossing the net and therefore the system didn't recognise the start of the point," the club said in a statement.
"As such the chair umpire instructed the point be replayed."