Victoria Azarenka has been forced to pull out of Wimbledon due to a knee injury.

The second seed was due to play Flavia Pennetta this afternoon but failed to recover from an injury to her right knee sustained in the first round.

During the first round match against Maria Joao Koehler did the splits near the baseline as she attempted to return a ball, but crumpled to the ground, atlhough she managed to complete the match after some treatment. 

(ESPN)