I'm confused.
A good manager would make an excellent psychologist. You have to manipulate your squad, cast aside any opinions (internal and external) on the players and find out how to motivate them. As heza pointed out, Shearer may have 'given them a kick up the arse' (or whatever) and it didn't work - obviously.
Why? Just ask a psychologist.
Maintaining discipline and moral are fundamental to a successful manager.
You still haven't justified your post.