Defending champion Kerber wary of Serena

LONDON - There are seven Grand Slam winners in defending champion Angelique Kerber's quarter of the draw at Wimbledon this year, but the German said she is only conscious of one particular opponent: Serena Williams.

Fifth-seeded Kerber kicks off her campaign against fellow German Tatjana Maria on Tuesday, but could potentially face three former champions in Williams, Garbine Muguruza and Maria Sharapova if she goes deep into the tournament.

Kerber won her third career major at the All England Club last year to add to her triumphs at the 2016 Australian and US Opens.