The former Red has been impressed by the improvement our No.14 has made under Brendan Rodgers this season and is tipping him to continue to develop.
Warnock told LFC TV: "I remember watching when they played at Arsenal and he was the best player on the pitch by a mile - the distance he covered and he seemed to be playing in a more advanced role.
"I've played against him and trained with him and know he's a very good player.
"I think the first year he came was probably a bit daunting for him in realising what Liverpool is all about and things like that, but I think he's acquitted himself well this year and been very good.
"People forget he's still young. He's 22 and still has plenty of time to be a great player for Liverpool."