Victoria Azarenka is one of five players to pull out of Wimbledon

World number two Victoria Azarenka is one of five players to pull out of Wimbledon on Wednesday after failing to overcome a knee injury.
The two-time semi-finalist fell heavily during Monday’s 6-1 6-2 first-round win over Maria Joao Koehler of Portugal.
Earlier, Steve Darcis, who beat Rafael Nadal in the first round, pulled out with a shoulder problem.

Number 10 seed Marin Cilic is also out with a knee injury while John Isner and Radek Stepanek were forced to retire. Azarenka, 23, had continued her first-round match after lengthy treatment and heavy strapping but failed to recover in time to face Italian Flavia Pennetta on centre court. Darcis, who was scheduled to play Lukasz Kubot of Poland. announced his withdrawal on Twitter: "Having to throw in the towel after beating Rafa!? THE hardest decision of my career!!! #triedmybestanyway!!!"

Neither Darcis or Azarenka took to the court for their second round matches."It happened against Rafa in the middle of the first set when I fell down," added Darcis."After the (Nadal) match, a few hours after, I start to feel so much pain, I couldn’t sleep that night. I saw the physio and the doctor yesterday. hey did a good job. It’s a little bit better today. But no chance I can play. I mean, I cannot serve. Even on the forehand side, I cannot hit a ball. It makes no sense to go on the court to withdraw after two games."

Both Isner and Stepanek required treatment during their second round matches but failed to recover enough to continue. American Isner had played just two games of his match against Adrian Mannarino of France when he was forced out with an injury to his left knee."Always serve and land on my left leg, like I have done 20 million times playing this game, and this is the first time I just felt this, like, sharp pain," he said."It wasn’t like a pop… it just grabbed really badly, and I knew I was in serious trouble then. I knew at that point it was not likely I was going to be able to play."

Stepanek soon followed, trailing one set to love and 5-3 to 24th seed Jerzy Janowicz, when he retired with a hamstring problem. Cilic made it five withdrawals when he pulled out ahead of his second-round match with Frenchman Kenny De Schepper. The world number 12 could have met Andy Murray at the quarter-final stage.