"You've got to tread a bit more carefully that you used to," said Redknapp, who last managed Birmingham City.
"It is a very different game now to manage the modern player. You can't be steaming into them every day because they don't have it anymore.
"Years ago, we used to sit there and take it, the manager used to shout and scream at you. Nowadays it is not done anymore.
"You can't manage like that. I don't know what has gone on there but it is very different now."
He added: "[They're] very, very sensitive. They've all got agents now.
"They ring the agents, who ring the chairman if you upset them. So you're treading on eggshells every day really."