Updated

By Martyn Herman

Many thought the 13-times grand slam winner's career was over when she suffered potentially fatal blood clots in a lung during her recovery after slicing a tendon in her foot on broken glass, an injury which itself required two operations.

She beat Vera Zvonareva in last year's final and the Russian got some revenge this week when she knocked out Williams in the second round at the Wimbledon warm-up event on the south coast.

With sister Venus also back from a five-month lay-off in time for the grasscourt slam the sisters have dominated for a decade, the women's tournament has suddenly been catapulted out of the shadow of the men's event.

"Double the excitement and double the intrigue," was how former Wimbledon great Chris Evert described the effect the American siblings would have in leafy south west London.

Any weaknesses in their games will be fully exposed over the two-week slog, however, and there are plenty of women capable of wrecking their comebacks.

World number two Kim Clijsters has withdrawn with a foot injury but China's Li Na, the French Open champion, world number one Caroline Wozniacki, former winner Maria Sharapova and Zvonareva will all be contenders, while the likes of Victoria Azarenka and Petra Kvitova could also go far.

"Serena is a great champion so it's always great to see great champions back on the tennis court," second seed Zvonareva told Reuters at Eastbourne.

MORE EXCITEMENT

"They add excitement to women's tennis and create another challenge."

That is why, despite their woes this year and fall in the rankings which means Serena is seeded seventh and Venus 23rd, it would not be a huge surprise to see them on opposite sides of the net in the July 2 final if the draw keeps them apart.

Neither will be worried by their lower rankings since Serena won the 2007 Australian Open while ranked 81 in the world and six months later Venus triumphed at Wimbledon as the 23rd seed, with both having returned from lengthy layoffs.

They have overcome adversity over the years, suffering personal tragedies such as the murder of one of their sisters as well as battling many injuries and instances of racist abuse.

All eyes will be on the baseliner as she tries to end the debate about her number one credentials and she will hope for a better showing than she managed last year when she was thrashed 6-2 6-0 by Kvitova in the last 16.

China's 29-year-old Li, the first player from an Asian nation to win a grand slam, has been the player of the year so far and her compact game is well-suited to the grass.

With an Australian Open runner-up finish and then her glorious run in Paris, she has proved she has what it takes to win the game's major prizes.

"I turned my phone off for three days," she said at Eastbourne this week.

"Everyone was going a little crazy. But I just want to prepare for Wimbledon now because I've always done well there."

Sharapova, beaten by Li in the French Open semi-finals, also thrives on grass courts with her full-on power tennis.

Provided she shakes off the illness that disrupted her grasscourt preparations she will fear no one in the draw, not even the Williams sisters.

(Editing by Brian Homewood and Sonia Oxley)