Olympique Lyon are demanding record money to sell superkid Willem Guebbels.
Geubbels has rejected a long-term contract with Lyon with his youth terms set to expire at the end of next season.
Arsenal, Manchester City, Chelsea, Barcelona, RB Leipzig and Bayern Munich are among those believed to be monitoring the 16-year-old's situation.
But Lyon president Jean-Michel Aulas told L'Equipe: "If Willem thinks he can have a better career in Monaco than Lyon... Monaco bought Pietro Pellegri for €25m. We will not make gifts.
"In any case, we try to have people with ethics. My biggest regret is never to have seen Willem alone, I'll talk to him about it directly.
"It is the end of his contract in 2019. If Monaco makes an offer of €70m we will be disappointed because we believe [in Geubbels] a lot.
"We are reassured by his valuation."