Olympic downhill skiing champion Lindsey Vonn is down for the count.
In a Facebook posting Tuesday, Vonn says she won't compete in Sochi next month at the Winter Olympics.
The reigning Olympic and world cup downhill skiing champ says a knee injury is forcing her to withdraw.
Vonn says she's devastated, but that her knee is just too unstable to compete at an Olympic level.
She injured her knee at the world championships 11 months ago.
The four-time world cup overall champion underwent reconstructive surgery.
But a crash during training in November aggravated the problem.
She says she's undergoing another surgery and plans to compete at the world championships in Vail, Colorado next year.