When asked by Sky Sports who the other club was, Warnock siad: "I can tell you that West Ham and Fulham aren't.
"We've agreed fees with a couple of clubs and obviously Middlesbrough have got the opportunity to speak with him first.
"I don't know if he's going to speak to anybody else but once we agreed a fee other clubs can quite rightly match the fee and talk to him.
"I'm pleased for Ben and for the club and the chairman. We had a derogatory offer of £500,000 from QPR and early on in the season it was unsettling for Ben.
"But we've got a realistic valuation now. I think £2million is realistic for someone of Ben's quality.
"I'll be sad to see him go, he's going to be a very exciting player."