This wouldn't be the first time Lindsey Vonn has defied odds.
She crashed so badly during a skiing training run at the 2006 Olympics she had to be airlifted off the mountains of Sestriere to a hospital in Turin, Italy.
Two days later, battered and bruised, she finished eighth in the downhill.
Vonn limped into the 2010 Vancouver Games with a shin so bruised she couldn't buckle her ski boot without excruciating pain. She refused X-rays for fear it would reveal a break that would take her out of the Olympics.
"Never discount how tough she is or how much she wants it," a U.S. ski team doctor said at the time.
Vonn took gold in the Olympic downhill.
The star of the American alpine team now faces another huge challenge less than 80 days before the 2014 Sochi Olympics.
It was announced Wednesday that Vonn suffered a partially torn right anterior cruciate ligament during Tuesday's training-run crash at Copper Mountain, Colo.
It was the same knee Vonn shredded at last February's World Championships in Austria. In that crash she tore her ACL, her medial collateral ligament and also suffered a fractured shinbone.
Vonn's rehab was reportedly ahead of schedule and she was only days from her comeback race next week at Beaver Creek.
What happens next is not yet clear.
Lewis Kay, Vonn's publicist, confirmed the injury in a statement but did not offer any definitive Olympic prognosis:
"She needs to rest for a few days and then will pursue aggressive physical therapy and will determine the next time she is able to compete after seeing how she responds to the treatment."
Vonn, 29, hasn't commented much on Twitter since she posted a Monday picture of her about to leave the start gate at Copper Mountain: "Catching some air today in Downhill training."
On Wednesday, she retweeted "Thx Weezy" to a get-well message sent from rapper Lil Wayne.
He wrote: "My prayers are with u Lindsey. Wishing u a speedy recovery."
Bert Mandelbaum, an orthopedic surgeon at St. John's Health Center in Santa Monica, told the Times a partially torn ACL could mean many things.
"This is not like being pregnant," Mandelbaum said after reviewing the statement from Vonn's agent. "There's degrees."
Mandelbaum is not Vonn's doctor and could offer only a general assessment. He is considered an expert on knee injuries and has worked with several sports teams including soccer's Galaxy and Chivas USA.
"It depends on where she is on the spectrum," Mandelbaum said. "That will determine what her medical team's next steps are."
Mandelbaum said the spectrum for a partial ACL tear is "1 to 10."
Bill Sterett, Vonn's personal orthopedic surgeon, was with the skier soon after her crash near Vail. He has yet to comment on the injury.
U.S. Ski Team medical director Kyle Wilkens said on the organization's website that Vonn's response to therapy "would ultimately determine the timetable for her return to active training"
Vonn's comeback from major surgery is one of the most anticipated stories entering the Sochi Olympics.
Her 59 World Cup victories are the most in U.S. Alpine history. Bode Miller is the U.S. men's leader with 33.
Vonn is a four-time World Cup overall champion and needs only four victories to surpass former Austrian star Annemarie Moser-Proell's all-time World Cup record of 62.