Lindsey Vonn withdrew from competing in the upcoming Winter Olympics in Sochi, she announced Tuesday, Jan. 7.

The news comes 11 months after the gold medalist skier underwent major knee surgery. The athlete hoped to defend her win in the downhill from the 2010 Winter Olympics.

"I did everything I possibly could to somehow get strong enough to overcome having no ACL but the reality has sunk in that my knee is just too unstable to compete at this level," Vonn said in a released statement.

"I'm having surgery soon so that I can be ready for the World Championships at home in Vail next February," the 29-year-old added. "On a positive note, this means there will be an additional spot so that one of my teammates can go for gold. Thank you all so much for all of the love and support. I will be cheering for all of the Olympians and especially team USA!"

Vonn also pulled out of the season's opening race in Soelden, Austria in October.

In February 2013, Vonn tore the anterior cruciate ligament and medial collateral ligament in her right knee and fractured her tibia after crashing in Schlamding, Austria, in the Alpine skiing world championships. She posted on Facebook a photo of her bruises and scars before undergoing surgery.

Nine months later, she partially tore one of the reconstructed ligaments in her knee after crashing a training run in Colorado.

"I don't think I was pushing myself too hard,'' Tiger Woods' girlfriend told Today after injuring herself in November.  "It just was unfortunately a fluke accident. That's the risk you take when you're going 80-90 miles an hour down a mountain. That's just part of the job, but I've picked myself back up, and I'm trying as hard as I can to keep going. I'm working as hard as I can."

Vonn has won an American-record four overall World Cup Championships. She is three wins shy of tying the women's record of 62 World Cup race victories set by Austria's Annemarie Moser-Proell.

Watch Vonn's crash from February in the video below.