Singh referred to Pedersen as "a pensioner" at an open meeting with fans last weekend and stated manager Steve Kean would be dismissed if he lost three consecutive Championship games early in the season. He has since apologised but that has failed to satisfy the PFA, who claim his comments upset a number of the club's players.
"The PFA have been in discussions with the players at Blackburn Rovers in relation to the recent comments made by Shebby Singh," read the statement. "We share their considerable disappointment that anyone connected to Blackburn Rovers would make such disrespectful comments about a player like Morten Gamst Pedersen."
The statement continued: "The feeling within the squad is that as a group of players they support each other but particularly someone like Morten, who is so respected within the club and indeed the game.
"Personal criticism of this nature is never acceptable and the players are shocked that someone from within their club has seen fit to make such comments.
"Whilst accepting that anyone can have an opinion on football, someone in such a position of responsibility should be more mindful of the comments he makes, particularly when you consider what a valuable member of the team Morten is and the great contribution he has made and continues to make to Blackburn Rovers and Norway.
"Any comments that are made should be based on fact, and it is our understanding that the club's statistics on Prozone over the last season completely disproves any such uninformed views."
Singh apologised earlier this week for his comments on Kean and Pedersen, telling the Lancashire Telegraph: "I would like to extend an apology to Steve Kean because some things were said on Saturday. I think they would have hurt Steve Kean's feelings and, for that, I sincerely apologise.
"Some things are said in jest that don't come across like that when repeated, but I am not making excuses. I apologise for hurting any feelings. I would also like to apologise to Morten Gamst Pedersen for what was said. There are no excuses and Morten is a great character.
"My blunt honesty also sometimes upsets people and sometimes rubs people up the wrong way. I am making efforts to bring the club back to the fans and, in trying to do that, I have gone too far. I am trying to find the middle ground."