Defending champion Petra Kvitova believes that her serve will be crucial to her chances of winning a third Wimbledon title in the space of five years.

The 25-year-old Czech left-hander was crowned champion at SW19 in 2011 and repeated that feat 12 months ago when she took the honours again, defeating Eugenie Bouchard in a one-sided final.

And Kvitova, whose preparations for her title defence have been badly hampered by illness and who has yet to play a match on grass this year, expects her lefty serve to again be crucial.

She told the official Wimbledon website: “My favourite shot at Wimbledon is the serve because I’m left-handed. This is always the most important shot for me.

“Whether I am facing a break point, or I have a match point, I have that serve and that’s great to have that.”

Meanwhile, 2014 runner-up Bouchard faces a race to be fit to feature at Wimbledon, having been forced to retire during her third-round clash with Belinda Bencic at the Aegon International.

The Canadian suffered an abdominal strain and called time when she was trailing 6-4, 3-0 to the rising Swiss star.

Bouchard, who is scheduled to be seeded 12th at Wimbledon after a difficult year which has seen her win less than ten matches, had earlier said: “I’ve really had some ups and downs this season. I’ve learnt a lot about tennis, myself and life as a result.”

She can be backed at 34.00 to win Wimbledon this year, while Kvitova is available at 4.50.