Germany’s Franziska Preuss will have to wait to make her return to the biathlon World Cup from a foot injury sustained from a staircase stumble. The German ski federation said Thursday the 27-year-old Preuss would miss the January 6-9 home World Cup in Oberhof but could return in Ruhpolding three days later. Preuss was told by doctors to rest for 10 days after twisting her left ankle at the last French events in Le Grand-Bornand, which she exited without competing. Preuss, along with Denise Herrmann, is considered one of Germany’s biathlon medal hopes for the Olympic Winter Games in Beijing fr…