Olympic champion ski jumper Kamil Stoch has picked up an injury around three weeks before the Winter Games and faces a race against time to make the event in Beijing. The 34-year-old Pole will sit out this weekend’s home World Cup jumps in Zakopane having hurt his ankle. “Warm up, second of no use, I don’t even know what to call it and the pain … Bone marrow and changed color. Several hours of treatments, consultations, diagnoses.” Stoch wrote on social media. Stoch has not been in great form this year having under-performed as defending champion at the Four Hills Tournament. He won two Olym…