Wheelchair tennis star Gordon Reid believes he would be unable to show his face on tour if he took a bathroom break for as long as Andy Murray's US Open opponent Stefanos Tsitsipas.

Former world number one Murray said he lost respect for Tsitsipas following his defeat at Flushing Meadows after the Greek disappeared for almost eight minutes ahead of the fifth set.

He then took a second swipe at the tournament's third seed by tweeting that his lengthy trip to the lavatory was double the time Amazon founder Jeff Bezos required to fly into space.

Reigning Paralympic champion Reid is on course to defend his singles title in Tokyo after setting up a semi-final showdown with world number one and home favourite Shingo Kunieda following Wednesday's three-set win over Gustavo Fernandez.

Murray's fellow Scotsman feels it is unlikely for there to be perceived gamesmanship of that nature in the impaired version of the sport.

"I don't think so. Definitely not in the men's division anyway, for sure," said Reid.

"I think everybody has a lot of respect for each other and we play each other at almost every event.

"I don't know if you'd be able to do that sort of thing and show your face the next time. Thankfully it's not an issue for us."

Glaswegian Reid initially feared his title defence was over without hitting a ball in Japan after a member of the GB tennis squad tested positive for coronavirus just a day before the opening ceremony.

That prompted the 29-year-old to make an emotional phone call home followed by a sleepless night.

He was eventually cleared to play but forced to follow a strict routine which included only leaving his room for matches and practice and not socialising with team-mates.

Those regulations ended ahead of Reid coming from 4-0 down in the opening set to defeat Argentinian Fernandez 7-5 3-6 6-1 in a repeat of his Rio 2016 quarter-final.

"This morning was the first time that I could get out and go to the food hall myself and not have it delivered to the room because it's 10 days since the test," said Reid, who has also reached a second consecutive doubles final alongside team-mate Alfie Hewett.

"I was pretty emotional because at that stage, him testing positive and us being around – not close contacts but still being in similar places for the last few days – was a scare.

"But it's not been an issue so far so I've got no complaints."

Hewett also booked his last-four singles spot, beating Frenchman Nicolas Peifer 6-3 6-4.

The Rio silver medallist will next face either Dutchman Tom Egberink or Spain's Daniel Caverzaschi, ahead of a potential final rematch with Reid.

Also asked about comfort breaks in wheelchair tennis, the Norwich-born 23-year said: "They go to the toilet but it's probably a bit different because of the medical needs that players have.

"If someone takes a bit longer you're not sitting there going, 'well you've taken seven minutes' because of the needs they might have.

"I don't feel like it is (abused) – not in our sport."