Two-time Wimbledon champion Petra Kvitova is a doubt for this year's tournament after she withdrew from the Birmingham warm-up with an arm injury.

The 29-year-old world number five, who lifted the singles title in 2011 and 2014, pulled out of her first-round French Open match last month.

"Unfortunately Birmingham is too soon," she wrote on Twitter

"I'm working really hard to get back as soon as possible and keeping everything crossed for Wimbledon."

Kvitova beat British number one Johanna Konta on her way to a successful defence of Birmingham's Nature Valley Classic title last year.

Her 2017 victory at the event was her first title since she was stabbed by an intruder in her home the previous December.

"I have the best memories of Birmingham," she added. "It was the first place that I won a title after I came back from my injury. I always have the best time there and I hope next year I will see you on the beautiful grass courts."

However Kvitova's fellow Czech Karolina Pliskova will be in the draw.

The world number three joins Australian and US Open champion Naomi Osaka and newly-crowned French Open winner Ashleigh Barty among the field.

It is the first time the Edgbaston tournament has featured the world's three best-ranked players. This year's event begins on 15 June.