In his column for The Sun, Redknapp wrote: "The very last thing boss Martin Jol needs right now is Dimitar Berbatov spitting his dummy out because he's not in Tottenham's starting team every week.
"You only find out the true character of your players when the chips are down and the pressure is on. And we all saw what Berbatov is made of when he was sat sulking on the bench at Newcastle the other night with a face like a big baby.
"Everyone knows what a terrific player the Bulgarian can be. He showed what he is capable of with 23 goals for Spurs last season. But he's not the striker he was a year ago and, from what I've seen, he looks to be disinterested and playing for himself rather than his team.
"His attitude is terrible and his behaviour at St James' Park sent out all the wrong signals. Maybe he's sulking because he didn't get a move to Manchester United in the summer.
"But he's done himself absolutely no favours on that account because I know for a fact Alex Ferguson would never stand for any player who behaves the way Berbatov has done this week. When your team is in trouble you need the big characters to stand up and show some b*******.
"That's just what Robbie Keane has done for Spurs and Berbatov should show the same attitude. I have always believed that when you lose a player's support you get him out as quickly as possible. No matter how good, you're better off without him."