Shiffrin crashed in a World Cup competition in giant slalom in Killington in November and got a deep wound that caused muscle damage in her abdomen.
In the World Championship, the plan was for her to make a comeback in the discipline, but that won't happen. The crash is still affecting the superstar, who has a total of 99 World Cup victories – the most of all time.
I'm mentally blocked in a way that I can't push myself to the next level of speed and when it comes to getting pressure in the turns, says Mikaela Shiffrin in an audio message that AP has received.
This type of mental, psychological problem similar to PTSD (post-traumatic stress disorder) is bigger than I had expected.
Shiffrin's decision to opt out of the discipline, which takes place on Thursday, opens up opportunities for her competitors – including Sweden's big gold hope Sara Hector.
The Swede has impressed during the season and has been on the World Cup podium five times – twice at the very top, and both times in giant slalom.
Mikaela Shiffrin still plans to compete in the World Championship slalom on Saturday. With the announcement that she is opting out of the giant slalom, she is also changing her mind about Tuesday's team competition, where one skier competes in downhill and another in slalom. The initial plan was not to participate, but now the announcement is that she will form the US team together with Breezy Johnson.