Klopp believes Virgil van Dijk has been a good influence on his defensive partner.
He said, "Joe has big potential, I'm happy, but more interested in his performance tomorrow. We have to deliver week in, week out.
"Both like each other. It's a good relationship. They like to play together.
"Virgil's presence helps. If Joe is not a fantastic footballer, it would not help. If you play with Van Dijk, it wouldn't work."