Campbell, 43, retired six years ago after two decades in the game and bemoans the fact that strong-tackling centre halves are a dying breed.
"Sometimes, you've got defenders who simply don't want to defend," said Campbell.
"Football has changed. Hard tackling seems to have gone out of the game.
"I don't know why that kind of training isn't around any more. To find the kind of really good defender like those we had in my day, that's gold dust."