Houllier said: "John Arne Riise came on last week and did very well at Blackburn. He is going to be in the team for some time now following the injury to Carra. One person's mis-fortune can be somebody elses happiness.
"Riise is a good defender but I think there are times when he needs to believe in himself a bit more. He could be like Roberto Carlos for us down the left. He can get up and down the field, he can score goals and he can create goals."