The England midfielder has captained Liverpool to their first Premier League title and their first league success in 30 years.
"I saw somebody who was better than what we had at that time in that position," the 69-year-old is quoted as saying by The Independent.
"That was on the pitch. Then when you get into discussions, he was very balanced, his dad came with him for the conversations, which was – for me – a good sign.
"He had a secure home life, which helps, and he was determined to be a success in football. If I hadn't given him a chance, it would have been me who would have been wrong. I'm not being modest – you see something you like and you get it.
"He will be the only Liverpool captain who has lifted this trophy, but is Club World Cup winner as well. He is up there with the captains who have picked up the Champions League.
"The great thing about the success I think is the common bond between everybody. You need a really good dressing room to be successful."