FIFPro has called on Turkey's football authorities to postpone the domestic season as the coronavirus pandemic continues.
While most European nations have paused the season due to the spread of the virus, the Turkish Super Lig has continued this week behind closed doors.
Midfielder John Obi Mikel had his Trabzonspor contract cancelled by mutual consent after stating publicly that he did not feel safe to keep playing.
FIFPro, the global professional footballers' union, has urged Super Lig organisers and the Turkish Football Federation (TFF) to review the decision to carry on.
In a statement released on Twitter, the union said: "FIFPRO has written to the Turkish #SuperLig and federation asking them to urgently reconsider the decision to continue matches and training during the #coronavirus outbreak
"Numerous foreign players have contacted us to say they are uncomfortable continuing as #COVID19 spreads."
Europe's top five leagues in England, Italy, Spain, Germany and France, as well as the Champions League and Europa League, are among the competitions to be paused during the pandemic.
Euro 2020 and the Copa America have been pushed back to next year to make it easier for the 2019-20 club season to be completed once the suspension on games is lifted.
There have been 191 confirmed cases of the virus in Turkey.