Redknapp left Crouch on the bench for their victory over Blackburn Rovers.
But he argues: "Crouch has to go to the World Cup. He seems to score every time he plays for England, he leads the line well, holds the ball up and wins every header.
"He gives you something completely different when games are tight. You can play long balls to him, he will win headers and (help) other players to get around the second ball and open packed defences.