PFA chief executive Gordon Taylor fears that black players may be reluctant to report racist abuse following the backlash that Anton Ferdinand has suffered.
A storm erupted when the Queens Park Rangers defender accused Chelsea captain John Terry of racially abusing him when the two teams met at Loftus Road in October.
Terry is still awaiting trial for the incident and Taylor believes that the amount of time the judicial process has taken could have a negative affect on any more players coming forward.
Taylor also believes that players may be put off by some of the chants that Blues fans have aimed at Ferdinand and some of the messages he has received on Twitter.
"If there is going to be such a backlash it could set back the process of complaining which is the process by which we can measure whether this is going on," said Taylor.
"The last thing I want after this season's incidents is for black players to not feel comfortable with the process, that if they do make a complaint that it won't be addressed properly.
"There's been a worry that the Terry-Ferdinand incident hasn't been dealt with yet, there's been a worry about what happened with the Liverpool reaction. I'm feeling frustrated that we can't be a bit more effective in that process."
Terry's case is due in court on July 9.