39-year-old Northug was struck by norovirus, winter vomiting disease, a couple of weeks ago and has not managed to recover after the tough illness period.
I felt that there was a bit of illness on the way. It became a few terrible days with toilet visits, rash, and fever, he says to Norwegian TV2, and continues:
I have no chance in the state my body is in now. I still can't train properly.
This is not the Norwegian's first setback this winter. Before Christmas, his season start was stopped due to back problems, and just over a month ago, he was disqualified from the long-distance race in Marcialonga after skiing freestyle on sections intended for classical style.
Vasaloppet takes place on Sunday, March 2.