could we offer medel a promotion clause contract?

Let's say for example we got promoted we would increase his wages by X amount.
if we dont get promoted, we will lower his valuation and allow him to leave.

Or even offer him small sign on fee until january... or end of season

Of course we could, but the question should be, should we?

He is under contract for three more years, why would we offer him anything, stuff Inter pay the money or piss off