Craig Brown insists Chris Maguire will only be allowed to sign for Derby County when Aberdeen's demands for compensation are met.
Maguire is out of contract at Aberdeen and appears to have decided to quit the SPL club in favour of a move to the Championship.
The Dons had been prepared to compromise on the length of contract required to keep Maguire at Pittodrie and Brown feels the striker is making a mistake in leaving.
He is understood to have agreed terms with Derby, but Aberdeen are entitled to compensation for the Scotland international.
Reports claim the Dons are looking for £400,000 and Brown is adamant the fee for the 22-year-old is not up for negotiation.
"We did everything to persuade Chris to stay," said Brown in the Press and Journal. "I'm convinced it would have been the better option.
"But we will not accept anything less than we feel we're due. The compensation is non-negotiable.
"He can only sign for Derby if they agree to pay what Aberdeen are looking for."