Shamil Tarpishchev told the R-Sport news agency that Sharapova’s situation was “bad”.
The five-times grand slam champion faces a possible ban of up to four years for failing a drugs test at the Australian Open in January.
British media reported that she had been due to attend an International Tennis Federation (ITF) anti-doping hearing in London on Wednesday.
There has been no subsequent comment by the ITF.
Sharapova stunned the world in March when she said she had returned a positive test for the Latvian-made heart medication which was added to the World Anti-Doping Agency’s (WADA’s) banned list from Jan. 1.
The world’s highest-paid sportswoman claimed to have been taking meldonium on doctor’s orders for 10 years and had failed to note that it had become a banned substance until hearing of her failed test at the year’s first grand slam.
She was provisionally suspended on March 12 pending the hearing, and has lost a number of her lucrative sponsorship deals.
She said at the time that she hoped she would be allowed to play again.
The World Anti-Doping Agency WADA said in April, after hundreds of athletes had tested positive for meldonium, that bans might be overturned due to a lack of clear scientific information on how long the drug takes to be excreted.