According to Sky Sport Italia, Bologna rejected Nottingham Forest's opening offer for the 24-year-old, who remains a target for Napoli, out of hand.
Ndoye did not formally ask to leave Bologna, but reportedly agreed personal conditions with Napoli in the hope that the two clubs can reach an agreement.
Forest is likely to go back for the winger while they increase their striving for a replacement for Anthony Elanga, who came to Newcastle earlier in the summer for £ 55 million.
The wing player impressed Bologna last season when they won the Coppa Italia, scored nine goals and offer six assists in his 41 games.