Aldridge said: "Harry is a boyhood fan like me and when the club you support comes in for you all you have to say is 'where do I sign?'.
"I think it is refreshing he has turned Manchester United down. It shows you what he has held on to from his childhood. A genuine Liverpool fan would not be able to contemplate signing for United.
"When you are young and at school the rivalry between the two clubs is very strong. You form a divide then and I am sure that is why he has turned them down flat now. I know it will go down well with the fans.
"So often when players sign for a new club you hear them saying they were fans as a boy. With Kewell it seems that he genuinely was.
"Liverpool are getting a bargain. I have made no secret of how highly I rate Damien Duff and it was good to see Liverpool chasing a player of that quality. But if you look at the price being talked about for Duff and the price of Kewell it is a big difference and it represents a really good deal.
"They have needed a wide player like Kewell and with him in the side I think you will see even more avenues opening up for Michael Owen. Kewell can play on the right or the left and he can score goals himself. He is a player who gets fans on their feet."