Andy Murray has insisted there is nothing in the courts of the All England Club that has led to the unprecedented number of injuries today.

On a remarkable day, seven players withdrew with injury and seven former number ones were knocked out, including the reigning Wimbledon champion Roger Federer.

All the while, Murray quietly slipped into the third round beating Yen-Hsun Lu in straight sets (6-3, 6-3, 7-5) to face Spain’s Tommy Robredo, the number 32 seed.

Among the former number one’s ousted was Maria Sharapova, who, during her straight sets defeat to Michelle Larcher, appeared to tell the umpire that the court was dangerous.

The 26-year-old said afterwards: “After I buckled my knee three times, that's obviously my first reaction. I don't think I've ever fallen three times in a match before in my career, so that was a little strange.”

The Australian Open champion Victoria Azarenka withdrew with an injury sustained after a slip in the first round.

She said: “I don't think it [the court] was in a good condition. I fell badly, my opponent fell twice.

“It would be great if someone who was responsible for these things looked at it because there's nothing that I did wrong to cause me to slip."

Azarenka was joined in the treatment room by Radek Stepanek, John Isner, Steve Darcis, Yaroslava Shvedova, Marin Cilic and Jo-Wilfried Tsonga.

However, Murray, whose win over Lu came on the court where Azarenka picked up her injury, said: “The court felt fine to me. But obviously a lot of players have been slipping. I don't know what that's down to.

“Injuries are part of sport. You never know. You can pick things up very easily.

“Obviously when you're playing, when you're practicing, then sometimes you can fall down the stairs, trip over your shoelaces. Who knows?”

The All England Club issued a statement saying: “There have been no changes in the preparation of the courts and as far as we are aware the grass court surface is in excellent condition.

“In fact we believe that it is drier than last year when the prevailing conditions were cold and wet.

"A grass court is a natural surface and will generally be slightly more lush in the first couple of days.

“Although a number of players have withdrawn injured, only one player has attributed this to slipping over on court."