The 18-year-old, who rejected a new contract offer from the Dons last month, has been cleared to hold talks with npower League One side Bournemouth.
Aberdeen would receive compensation for the player if he left when his current deal expires in the summer, but Brown does not believe a move to the south coast is guaranteed.
"It is not a given he will go there," Brown told Sky Sports.
"It's clear we will be looking for more money than we'd be entitled to at the end of the season.
"What happens next is between Ryan, his agent and Bournemouth."
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