The Argentina international playmaker had previously been linked with a loan move this summer – with Championship outfit Leeds United reportedly keen on the 18-year-old.
Buonanotte played a key role for Albion at the tail end of last season as he helped the club to sixth in the Premier League and Europa League qualification.
De Zerbi previously said that a loan move was possible for the former Rosario Central man and would not be able to promise him the minutes this campaign as Solly March and Adam Lallana have returned from injuries.
Buonanotte, who arrived for around £10m last January and is contracted with the Seagulls until June 2027, looked to be on his way this summer but an injury to Julio Enciso scuppered any plans. Enciso is expected to be out for four months and will miss the entire group stage of the Europa League campaign.
Albion have also drafted in top talent Ansu Fati on loan for the season from Barcelona but De Zerbi insists that it’s not at the expense of Buonanotte, who will have a big role to play in the coming months as Brighton compete in the Premier League, Europa League, Carabao Cup and FA Cup.
Asked if Buonanotte will leave today in his pre-Newcastle press conference, De Zerbi said: “Buonanotte, absolutely no. I think he is in the right space and in the right space for me. He is [born in] 2004, he has to spend time like Julio Enciso and Evan Ferguson [did] in the last part of last season but I have big confidence in him.
"He is improving, from part of September to October [we] will play 10 games and he has to arrive in a good condition because he will play part of these 10 games.”