Australian Rafter has a knee problem and has been ordered to rest by doctors.

His withdrawal means British number one Henman and Karol Kucera of Slovakia will definitely qualify for Hanover, with Greg Rusedski and Yevgeny Kafelnikov vying for the final place.

"It isn't something that needs surgery. It's a bruised meniscus and it just takes time," said Rafter, the world number three.

"I've decided to pull out of Hanover because the doctor thinks I need to rest for a couple of weeks. Obviously this is a big disappointment. Everyone wants to play in the championships, they're the biggest event of the year. It would have been a good opportunity for me."