After a miraculous recovery from ACL surgery last season, Johnson is back on the sidelines with a torn MCL and PCL.
Shiffrin and Vonn set to return to racing in coming weeks.
Shiffrin wins Lake Louise Super G, becoming the first ski racer to win all six World Cup disciplines.
American Cochran-Siegle places 11th in a stacked international field.
The rising star on the U.S. Ski Team is out of the running after sustaining an ACL tear.
Vonn sixth in Super-G and Voisin just misses the slopestyle podium during a day of great skiing but no medals for Team USA Women.
Sweden's Hansdotter wins gold while Mikaela Shiffrin misses the podium in the women's slalom; Austria's Mayer wins the men's Super-G