Edwards was at fault for Port Vale's winner which knocked Stanley out of the FA Cup on Friday and Coleman has told the defender he needs to improve on his recent performances.
"It was a stupid goal we conceded, it was an individual error by Phil Edwards and that's about the fourth one he's made this season," he told the Lancashire Telegraph.
"He's been our most consistent performer over the last four years. He was the best defender in the league in my opinion but obviously my opinion now is somewhat tainted by what I've seen in previous years.
"This season he's a shadow of himself. Phil only had to head the ball away but he thinks he's got time and space three yards out and tries to chest it. It doesn't make sense."