Sergeeva was one of the 168 Russian athletes who were specifically vetted before the Games by the IOC, which had banned Russia's Olympic federation from Pyeongchang over past doping sins but allowed the preapproved Russian athletes to compete under the Olympic Athletes From Russia moniker. She's now the second Russian athlete — and just the fourth athlete overall — to fail a doping test at these Olympics, joining curler Alexander Krushelnitsky, who tested positive for the banned substance meldonium.