Redknapp is banking on Defoe's goals to keep them in the top four hunt.
"We are waiting for him to suddenly have that burst of goals that could make the difference to us," Redknapp said.
"If he can go on a run and score some goals he can take us where we want to go. We are relying on him. He is a fantastic finisher.
"Goalscorers need confidence. The other night he had a couple of one on ones that he would normally score (but) once they do start going in for him he will start going on a run."