Heerenveen coach Gertjan Verbeek is angry with speculation over Manchester City's interest in Afonso Alves.
He said: "The transfer window hasn't even opened yet but the stream of reports are under way already. It's no fun, but that's how it is.
"Journalists see a couple of scouts in the stands and Alves is sold immediately.
"Some newspapers even wrote that City have already paid us the transfer fee but we must deny those reports."