Novak Djokovic has urged Wimbledon to re-think its start times as he prepares to play for the third day in a row.
The defending champion takes on Andrey Rublev in Tuesday's quarter-finals, having played his previous match against Hubert Hurkacz over two days.
Play starts each day at 13:00 BST on Court One and 13:30 on Centre, with a 23:00 curfew resulting in some matches being suspended until the next day.
"I think the matches could be pushed at least to start at 12:00," he said.
"I think it would make a difference."
He described how he had spent seven hours waiting for his fourth-round match against Hurkacz to start on Sunday because the earlier matches ran long.
And he then had the opposite issue when the matchup resumed for a fourth set on Monday, with the preceding tie finishing quickly because Beatriz Haddad Maia retired injured after just 21 minutes of play against Elena Rybakina.
"I think there are different ways that I'm sure they will address this issue and try to avoid having these kind of problems in the future," Djokovic said.
Sally Bolton, CEO at the All England Lawn Tennis Club, said on Monday there was no guarantee an earlier start time would be considered on Centre Court for next year's tournament.
Djokovic said he hoped he would recover and be as fresh as he possibly could be when he meets Russian seventh seed Rublev for a place in the last four.
Rublev - aiming to reach his first Grand Slam semi-final - got his five-setter in the previous round finished on Sunday, and so meets the 23-time major champion having had a day of rest.
And, with a 3-1 losing record against the seven-time Wimbledon winner, he will be glad of it.
"Novak is one of the best players on grass, the player who [in the] last couple of years almost doesn't lose on grass. In my case, nothing to say. Just to go there and to try to do, to fight, do as best as I can my job."
Safiullin aims to continue life-changing run
Tuesday's other men's quarter-final pits Italian eighth seed Jannik Sinner against Russian world number 92 Roman Safiullin, who had never been beyond the second round at a Grand Slam until now.
He might have done at last month's French Open - but he forgot to enter the qualifying tournament.
The 25-year-old, who does not have a clothing sponsor and is staying in a budget hotel, is hoping his life will change after guaranteeing himself £340,000 for progressing to this stage.
Not that he will be changing hotels.
"Why should I change it?" he said. "Of course it's not like five stars, but I like the bed."
Swiatek and Svitolina meet after thrillers
Two of the best matches at Wimbledon this year came on Sunday in the women's fourth round and the winners of those thrillers will meet in the last eight on Tuesday.
World number one Iga Swiatek, who saved two match points to get past Belinda Bencic, takes on Ukraine's Elina Svitolina, who won a superb three-setter against Victoria Azarenka in what she called "the second happiest moment" of her life after giving birth.
Swiatek has worn a yellow and blue ribbon on her hat in support of Ukraine since the Russian invasion and Svitolina is grateful for the support the world number one has shown.
"I'm really thankful for her support of Ukrainians, Ukraine, doing everything that is in her power, being vocal about that," said Svitolina, who lost her only previous meeting against Swiatek on clay in Rome in 2021.
Swiatek is chasing a fifth Grand Slam title, while Svitolina is still seeking a first, having reached the semi-finals at Wimbledon and the US Open in 2019.
Since returning from having her daughter in October last year, she has reached the quarter-finals of the first two majors she has competed in.
American fourth seed Jessica Pegula and 2019 French Open runner-up Marketa Vondrousova of the Czech Republic meet in the day's other women's quarter-final.
Both have dropped only one set on their way to the last eight and are enjoying their best ever runs at the All England Club.
Elsewhere on day nine, there are British players in action in the doubles, with Jamie Murray and Neal Skupski seeking to reach the men's quarter-finals with their respective partners Michael Venus of New Zealand and Dutchman Wesley Koolhof.
And in the mixed doubles, Jonny O'Mara and Olivia Nicholls play a quarter-final against Australian fifth seeds Matthew Ebden and Ellen Perez.