Former Wimbledon champion Petra Kvitova has admitted that the leading players in the women's game will need to be at their best to have a chance of defeating Serena Williams.
Williams has won Wimbledon on five occasions and is currently on a 31-match unbeaten streak, and Kvitova knows that it will be tough to deny the 31-year-old her sixth crown.
The 23-year-old told Reuters: "I think that the players have to be at 100%, and to play really, really well.
"Serena sometimes doesn't have a great day but she's still able to beat the other players."
Kvitova won Wimbledon in 2011, defeating Maria Sharapova in the final.
