Arsenal offered €48m for Sampdoria pair Joachim Andersen and Dennis Praet, but the Blucerchiati want at least €55m.
According to La Gazzetta dello Sport reporter Nicolò Schira, the initial proposal has been rejected.
The Gunners are going to have to raise their bid, because Samp consider centre-back Anderson to be worth €30m on his own, with midfielder Praet valued at €25m.
Milan are also interested in the pair, but particularly Belgium international Praet, as they are about to hire Sampdoria Coach Marco Giampaolo.
Arsenal already did business with Sampdoria last summer, purchasing Lucas Torreira for €30m.