With star forwards Mo Salah and Roberto Firmino out injured, and centre-back Virgil van Dijk and midfielder Alex Oxlade-Chamberlain late doubts, Klopp confirmed the Reds' England Under-17 striker will play some part.
“He's ready, yes. There is a big chance. It's nearly sure. It's guaranteed," he said of the 19-year-old Londoner's involvement.
“Rhian has now arrived with us after being heavily injured. Day by day, he has got better and better and he has been in just outstanding shape for the last three or four weeks but the other players were there as well.
“Next season he will be playing 100%, and he knows that. I have told him already. It's really nice in a difficult situation that we can give him that spot in the squad and have him there to bring on as a striker. When you're on the bench, you are an option to play."