Victoria Azarenka, Jo-Wilfried Tsonga, John Isner lead injury withdrawals at Wimbledon

Tough news for Women's No. 2 seed Victoria Azarenka, as the knee injury she suffered in Round 1 (above) has forced her to withdraw from the tournament just prior to her second-round match.

Azarenka leads a list of notable injury retirements. John Isner had to retire almost immediately from his match with Adrian Mannarino because of a left-knee injury. It's especially unfortunate for Isner because he had never reached the third round of Wimbledon and was the highest-ranked player left in a bracket blasted by upsets.

Also retiring: Steve Darcis, who pulled off the stunning upset of Rafael Nadal on Monday, and Radek Stepanek, who retired late in the second set against Jerzy Janowicz. All four retirements came within a two-hour span on Wednesday morning and early afternoon.

Soon afterward, Jo-Wilfried Tsonga, the No. 6 men's seed, bowed out because of injury after losing two sets.

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