World 100 metres record holder Asafa Powell said Tuesday he has withdrawn from the Sydney grand prix athletics meeting on Saturday with a cut knee.
The Jamaican said he had four stitches inserted after gashing the knee while running up the stairs at his home in Jamaica last week.
He arrived in Australia on Monday, a day later than scheduled after missing a connecting flight in the United States.
"I was running up the stairs at my house and I fell," he told reporters Tuesday.
"And once a big guy like me falls on my knee it's not going to be pretty.
"I fell on my knee and got a cut and had some stitches in it and hopefully it's going to be better soon.
"Now is not a bad time to get (the injury) because this week is an easy training week so it's not that bad.
"I hope it gets better by the weekend so I can start doing some training."
Powell said he is now aiming to be fit in time to run the 100m at the Melbourne Track Classic on February 21.
"It's getting better day by day so ... I'm very confident about running (in Melbourne)," said Powell.
"The good thing is that I am here and I've wanted to be here for a while now."
Powell and his sprint squad chose to begin their Beijing Olympic preparations in Australia after he said he enjoyed his time here before winning the Commonwealth Games 100m gold medal in Melbourne two years ago.
Despite holding the 100m world record of 9.74 seconds, Powell is still yet to win gold at either world championship or Olympic Games level.
His showdown with American world champion Tyson Gay in Beijing is expected to be one of the highlights of the 2008 Olympics.