The United Soccer League Players Association says it has lost confidence in the Chattanooga Red Wolves' investigation of allegations of misconduct by coach Jimmy Obleda.
The group is asking the US Center for Safe Sport to take it over.
The USLPA said it initially brought up the matter after 18 current and former players and former technical staff approached the group.
The USLPA said all 18 said they had experienced or observed "foul, degrading and abusive language" from Obleda.
The group said it confirmed that Obleda "engaged in bullying conduct."
It said the players said they were fearful of retaliation from the club and said the club did not take steps to deal with the allegations.
The statement said the actions of Obleda "repeatedly put players in harm's way."
It says some players felt "mentally destroyed" and considered giving up soccer.
Obleda was placed on administrative league. The players said there had been no assurance that he would not return.