Lindsey Vonn of the US arrives for a training session ahead of the Women's World Cup Downhill skiing race in Val d'Isere, French Alps, December 18, 2013. [Photo/Agencies]

Kay said Tuesday an MRI "showed an MCL sprain, which coupled with the torn ACL, has made it impossible to stabilize her knee and be ready to safely ski again next month."

Now Vonn will turn her attention to the 2015 world championships in Colorado. There's also this: She needs three wins to match the World Cup record of 62 race victories set by Annemarie Moser-Proell of Austria.

"I have every ounce of confidence that Lindsey will be in the starting gate next World Cup season, ready to compete," said Bill Marolt, the CEO and president of the US Ski and Snowboard Association. ``She knows the hard work it takes to get to the top and still has significant goals to achieve in what has been an incredible career."

US racers captured eight Alpine medals four years ago, their highest total at any Olympics and twice as many as any other country at Vancouver.

That figure may be tough to reach with Vonn sidelined and Bode Miller, who won three medals in 2010, trying to return to form at age 36 after left knee surgery. What's more, Mancuso has been struggling this season. Off to a poor start in pre-Olympic races, Mancuso recently headed home for a short break.

"We have a strong team that is well prepared... Now is the time for those athletes to step up," Marolt said.

Vonn, meanwhile, will go through another operation, another rehab, another road back.

"You need to look at the long run. The problem with the knee is there is not an insignificant risk that you're going to do more long-term damage that can't be repaired," said Kildow, her father. "So have it repaired now. So you can compete in future years. So you can ski and enjoy yourself after you get done competing."

More photos of Vonn and Tiger:

Woods and Lindsey Vonn announce dating

AtNew York fashion show

Aching Tiger anchors US triumph