Cyprus’s Marcos Baghdatis couldn’t keep his footing against Bulgaria’s Grigor Dimitrov on Thursday. (Oli Scarff/AFP/Getty Images)

WIMBLEDON, England — On its inevitable Twitter account with its 23,700 followers, the Wimbledon roof stopped by this week to sulk over its own uselessness. Deep in its retractable soul, it realized that even a posh roof that cost tens of millions of pounds has no purpose at a sun-scorched tournament that seems as if happening in some Wimbledon, Arizona.

Well, on Friday morning, they did find a use for it. They used it before the day’s Centre Court matches to give the grass some time off from . . . the sun. The roof, finished eight years ago as humanity’s stand against elements and the rain delays that used to mark and irk Wimbledon, finally went into action . . . over the galling lack of elements.

What a planet.

The first week of this tournament has been marked by clouds that have been feckless and fluffy. The temperature has frequented 85 degrees, the announcements on train platforms include advice about what to do if feeling “unwell” from the heat, and Wimbledon has turned into even more of a psychological examination than usual.

So the players spent parts of Friday answering about the effects of the dry, slippery grass, following upon the direst comments Thursday evening from No. 14-ranked Kristina Mladenovic of France, after her second-round loss to the American Alison Riske.

Having played Court No. 18, the one with the singular setting viewable from various levels, Mladenovic’s points included, “There’s no grass. I don’t know how to describe it. It’s not even clay. It’s not flat.” And: “I heard lots of complaining [from players].” And: “I mean, it’s quite unique with your opponent, after two games, you both agree on stopping playing in a Slam. You asking the referee to tell you what’s the rule if the both players don’t want to keep on playing. And the answer is that they just can’t do anything, unfortunately, and you have to keep on playing.”

She kept reiterating she was not trying to be critical. “I’m not an expert at all on grass courts,” she said. “I guess the climate doesn’t help, the fact that it’s too nice, too hot, too sunny, makes everything very dry. That’s what we got as an answer from the officials.”

It was four courts down Thursday on Court No. 17 that the American Bethanie Mattek-Sands suffered a grisly knee injury and screamed for help, even though as of Friday evening, the Women’s Tennis Association had been unable to track down any news of Mattek-Sands’s condition.

Meanwhile, the usual cacophonous symphony of players might have left hints about themselves as they opined about the grass.

Venus Williams, the five-time champion who edged rising 19-year-old Naomi Osaka, 7-6 (7-3), 6-4, to reach the fourth round, played the part of the focused veteran of 20 Wimbledons: “I mean, you have a slip or two. But that’s grass. I can’t say I’ve slipped more than usual.” Rafael Nadal, the clay-court Godzilla and two-time Wimbledon champion who beat No. 34-ranked Karen Khachanov, 6-1, 6-4, 7-6 (7-3), played the guy who likes a dry, firm court when he sees one and said, “Is better obviously for me.”

He said, “No, I didn’t. Not yet. Hopefully not. I didn’t slip yet.”

The No. 46-ranked Frenchman Benoit Paire also played on Court No. 18, on Friday, and after he slid through the 2013 semifinalist Jerzy Janowicz, 6-2, 7-6 (7-3), 6-3, he learned yet another English word and played the wily strategist. He asked French journalists how to say “slippery,” and then he said, “It’s only on four or five points or sometimes you slip. You slip? But I think during the match the court was not so bad. It’s like every grass court was. I think sometimes it’s a bit ‘slippy,’ but I try to stay focused and it’s the same conditions for both. We have to play in these conditions. We have to fight. We have to play, like me, I played some drop shots because I know it was ‘slippy,’ and I wanted to try something else.”

Janowicz, a big, tough lad who has fought injuries in recent years, said he had no problem with Court No. 18.

When Centre Court had had its shielding and its three-match day, it ended Friday with Andy Murray wrestling a tough thing away from No. 29-ranked Fabio Fognini by 6-2, 4-6, 6-1, 7-5. Fognini, the practical realist: “No, was really bad, the court. But they do the best that they can. It’s not their fault. I think this year was really sunny days, so the grass is not really good like years.”

Murray, also the practical realist: “In terms of moving on the court, I’ve felt fine. The court, I don’t think, is in as good of conditions as previous years. There’s quite a few spots on the court, like just behind the baseline and just in front of the baseline, where there’s quite big lumps of grass, sort of almost like little divots there, which I don’t remember really being the case. I don’t know if it’s anything to do with the weather they’ve had over the last, you know, few weeks and months.”

The No. 2-ranked Simona Halep, 25, was the budding veteran: “I cannot say the courts are bad because we know that the grass is like this. But I think because of the heat, the grass is a little bit too dry. Also the spots that the grass is gone, it’s a little bit dangerous. Yeah, I slipped a little bit at the beginning of the match. I was a little bit worried. But it’s normal and the conditions are the same for everyone.”

Then there were the two diplomats, having spoken Thursday. Novak Djokovic, who will oppose the one-time top-10 player Ernests Gulbis on Saturday: “The groundsmen of Wimbledon are the best in the world, by far, on grass courts. So they are making sure to keep the courts in good conditions and well-kept. They can do only so much. Sometimes if you make a hole or something like that, you know, it’s hard to kind of find a way to recuperate that . . . It’s something you get used to.”

And Roger Federer, who will play the No. 30-ranked 29-year-old Mischa Zverev on Saturday: “I mean, it’s always been like this. Now, is it more this time around? Possibly, because it’s been extremely hot today and yesterday. So that’s why maybe, that’s what we are hearing. It’s not a good sign, and you should always take the players’ opinion seriously, especially when both say it.”