Lewis Grabban scored a second-half hat-trick to condemn Oldham to defeat and Dickov was far from pleased with how "mentally weak" his players were.
"It was disappointing and embarrassing, especially the second half, and I won't be forgetting it for a long time," Dickov told the club's official website.
"To concede the goals in the manner we did is more than disappointing. I am embarrassed for the fans who travelled a long way and didn't deserve that.
"We might have good footballers but, if they are mentally weak, they are not going to have a chance.
The result saw Oldham slip into the bottom four after the defeat.