NFL Players Association president JC Tretter wrote in a blog post that the NFL "is unwilling to prioritize player safety and believes that the virus will bend to football."
The NFL has cut the preseason down to two games, but the NFLPA would like to eliminate it altogether.
According to Tretter, the NFL has not provided a medical reason for insisting on two preseason games. A source said last week that the NFL felt it needed to have some preseason games to evaluate rosters as well as to give teams practice under new pandemic-related travel protocols.
"Every decision this year that prioritizes normalcy over innovation, custom over science or even football over health, significantly reduces our chances of completing the full season," Tretter wrote.
The NFL has yet to complete its plan for regular season implementation.
"We don't want to merely return to work and have the season shut down before we even get started," Tretter wrote. "The NFLPA will do its part to advocate for player safety. We will continue to hold the NFL accountable and demand that the league use data, science and the recommendations of its own medical experts to make decisions. It has been clear for months that we need to find a way to fit football inside the world of coronavirus. Making decisions outside that lens is both dangerous and irresponsible."