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

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. Serena was her victim in the 2018 final as she avenged her loss to the 23-time major winning American in the final two years earlier.