US Open casualty Stefanos Tsitsipas appeared to take aim at Alexander Zverev following cheating accusations amid growing criticism over the world number three's long bathroom breaks during matches.

Tsitsipas vented his frustration after the under-fire Greek star suffered a shock 6-3 4-6 7-6 (7-2) 0-6 7-6 (7-5) third-round defeat to teenage sensation Carlos Alcaraz in New York on Friday.

Andy Murray said he "lost respect" for Tsitsipas over his excessively long bathroom break during Monday's thrilling five-set encounter at Flushing Meadows, while German star Zverev accused the third seed of behaving like a junior and disrespecting his opponents by taking such breaks.

It comes after Zverev appeared to accuse Tsitsipas of communicating with his father and coach, Apostolos, when he took a break during their semi-final showdown at the Western & Southern Open in Cincinnati this month.

Tsitsipas responded by denying having ever used his phone during such a situation, describing the accusation as "absolutely ridiculous."

As Tsitsipas' US Open campaign came to an end amid boos from the crowd, the French Open runner-up was again asked about the situation during his post-match news conference.

"I'm not pretending that everyone loves me. My intentions are not to be loved by everyone," Tsitsipas told reporters. "Every person can choose their favourite player, pick a side. I felt that way, but I kind of have ignored it.

"When people are not really in the sport and don't know what is happening, I mean, all these accusations have been completely false. The one in my match in Cincinnati, which was the most ridiculous thing I've ever heard in my life. I don't know what to say. That really shows the level of the person that said it.

"Then the crowd here, I guess these two things were the most intense that took place here. I was surprised in a way. I don't really let myself take me down because I'm out there playing my game. Fan support is important, but I just need to go out there and perform. It doesn't matter at that point.

"I know all of these things have been against me for no reason. I took my toilet break as a normal athlete. Might have taken a bit longer than other athletes. But if there is a rule that says there's a specific amount of time that you are allowed to take, then I would probably try and follow that protocol, that rule, and stay within the guidelines and try and follow it as much as possible.

"But I feel like, people, they don't understand. They are here for the show. They want to watch tennis. They're very impatient, especially the new generation. They just want to get it done quick.

"For me the only thing I did is change from wet clothes to dry clothes. Apparently it's a huge issue. Especially -- actually not especially.

"When no one discusses other things such as players taking more time than they're allowed to take, that has been an issue for me in the past playing against these players, getting cold, not feeling my game, having to wait more than 30, 35 seconds in between serves that I had -- in one of my matches here I had to wait very long time between first and second serve. I didn't complain. There is not a rule for that that says how much time you have to take between two serves. But I respected it.

"Then you have these players that everyone knows they're taking so much time but no one says anything. I don't know why everyone suddenly is against me, especially when other players don't follow rules and don't stick within 25 seconds between play."