By Martyn Herman

LONDON (Reuters) - World number two Kim Clijsters has withdrawn from Wimbledon with a foot injury, organizers of the grasscourt grand slam said on Wednesday.

Clijsters, the current U.S. Open and Australian Open champion, issued a statement through the referees office saying she had injured her foot at the Den Bosch Open on Tuesday.

"I'm very, very disappointed to have to withdraw from Wimbledon after injuring my foot again at the tournament in Hertogenbosch," said Clijsters, who was the second seed.

"At this moment I feel frustrated that it has to happen now before one of my favorite tournaments.

"I've always enjoyed being a part of the Wimbledon atmosphere but I have no other choice now but to rest, recover and to not play tennis for a few weeks."

The Belgian's withdrawal means last year's runner-up Vera Zvonareva from Russia becomes the second seed having originally been seeded three.

The popular Clijsters, who won the 2009 U.S. Open just three tournaments into a comeback from a two-year retirement in which she gave birth to a daughter, has had her season disrupted by injury since beating China's Li Na to win the Australian Open.

She injured her ankle while dancing at her cousin's wedding, resulting in a two-month lay-off, and although she returned to play in the French Open she struggled and was knocked out in the second round by Dutch world number 114 Arantxa Rus.

Serena Williams, the reigning Wimbledon champion who has just returned from an 11-month absence because of injury and health problems, rises to number seven seed.

The seeding committee had earlier bumped up the American from her world ranking of 26 to take into account her formidable record at the All England Club.

Last year's beaten Wimbledon semi-finalist, Tsvetana Pironkova of Bulgaria, is seeded 32, meaning she will avoid any of the big names until the third round.

(Reporting by Martyn Herman; Editing by Ken Ferris)