American two-time Olympic champion Mikaela Shiffrin announced on Friday a back injury has forced her to skip the alpine skiing World Cup season-opener in Solden on October 17. "After tweaking my back skiing last week, I have been advised to sit Solden out to let my back heal so I can race the rest of the season," she posted on social media. Shiffrin called a premature halt to last season to mourn the death of her father. Her run of three successive women's World Cup alpine skiing champion titles came to an end when she finished second to Federica Brignone. Shiffrin said it felt "frustrating and strange" to miss the giant slalom in Austria for the first time in nine seasons. She added: "Luckily, this injury will heal and I will be back in the start soon... (and I can't wait)." tba/nr/td