Tombi A Roko, president of the referees' commission, corroborated the stories of his colleagues.

BBC: SPORT | Football | African | Cameroon referees cry for help

Martin Vassallo Arguello and Brian Dabul, both of Argentina, and Croatia's Roko Karanusic will replace the injured trio in the main draw.

BBC: Stepanek doubtful for Wimbledon

Second seed Gonzalez, seventh in the Masters Cup race, overcame Croatian qualifier Roko Karanusic 6-4 7-6 to set up a meeting with unseeded Finn Jarkko Nieminen.

BBC: Federer brushes aside Del Potro