Juventus and Atletico Madrid have been told by Atalanta general manager Umberto Marino that it will take an offer of more than €50million to sign striker Duvan Zapata.
Colombia international Zapata has netted 17 Serie A goals this season for free-scoring Atalanta, who climbed into second place with Tuesday's 1-0 win over Bologna.
He has been strongly linked with a move to domestic rivals Juve and LaLiga side Atletico, with the latter rumoured to have had an opening offer of €50m knocked back.
However, Marino is holding out for a far bigger sum for a player who has netted 40 goals in two league campaigns with Atalanta since joining from Sampdoria.
"He is worth much more than €50m. They have to raise their bid," Marino is quoted as saying by Sky Sport Italia.
"But it is early to talk about it. We have to enjoy the Champions League and what remains of the season.
"He is doing well in Bergamo and I am happy that great international teams are looking at him."