Colorado Avalanche and Russia forward Valeri Nichushkin is facing an allegation of doping from a sample taken back in 2013.
The 26-year-old - who has represented the Avalanche for two years - has until November 16 to respond to the allegation over a sample which was obtained by WADA two years ago.
Russian Hockey Federation executive director Dmitry Kurbatov has affirmed that the case is yet to be cleared up, though, telling Tass State News Agency: "His sample from 2013 was being stored at the laboratory.
"During the process of reanalyzing results in January and February 2019 a banned substance was found and this case was initiated. There are no decisions yet and nothing has been cleared up."
Nichushkin registered 11 goals and 13 assists in the regular season and playoffs for the Avalanche last term, and any suspensions would reportedly only impact his international participation rather than his NHL commitments.
Russia have seen two of their Olympic triathletes hit with three-year doping bans over the past few weeks after traces of EPO were discovered in samples.