Warnock, speaking to reporters about his plans for the summer transfer window, believes that Willock will cost at least £20 million this summer after impressing on loan at Newcastle United.
Speaking about the summer, Warnock told Teesside Live: "We're talking to one loan target in particular at the moment, that we're hoping we can get in.
"He's at a Premier League club, and we've liked him ever since I've been at the club really. We'll try and see if we can talk him into coming up here. There's not a lot like that out there though.
"The real top ones of the 19 or 20-year-olds, they're probably going to get higher up than us. I don't mean that disrespectfully, but clubs in the Premier League will want them.
"Look at (Joe) Willock at Newcastle – I like him, but he's probably going to go for about £20m if they get him.
"The top ones are beyond us, so we have to look a little bit below or for someone we can nurture. We think we can with this lad, and I'm still optimistic. I think I'm talking to his dad later this week."