Ahead of her planned retirement after Sunday's downhill race, Vonn was treated by medical personnel after crashing Tuesday and skied down the hill.
Writing on Instagram, Vonn said "it’s been an emotional 2 weeks making the hardest decision of my life, but I have accepted that I cannot continue ski racing."
Vonn has left everyone guessing over her next move after announcing on Sunday that she was considering immediate retirement because of severe pain in both of her knees.
By winning Saturday, Shiffrin also became the first skier, male or female, to win 15 World Cup races in a single calendar year.
“It was one of my big goals to win in every discipline when I first started racing — one of those goals that you don’t think you are ever going to achieve,” the 23-year-old Shiffrin said.
Her firm retirement plans changed when she hyperextended and sprained a ligament in her knee during a training crash on Nov. 19.
It was World Cup slalom win No. 34 for Shiffrin, tying her with Vreni Schneider for second among women in the discipline.
The 34-year-old ski racer enters the season with 82 World Cup victories, leaving her five away from breaking the record held by Ingemar Stenmark of Sweden.
Even the most die-hard soccer fans watching games at the British Bulldog in downtown Denver this week say the sport may never be widely embraced in the U.S.