Napoli have received guarantees from Galatasaray they would be paid the €50m upfront and receive the rest of the €75m release fee in installments starting from Wednesday.
Both clubs have been engaged in long drawn talks for the transfer of the striker who guided them to a Turkey domestic double last season.
Meanwhile, Galatasaray fans have threatened to “deal” Napoli president Aurelio De Laurentiis and his son Edoardo have received death threats from Galatasaray fans if they refuse to let Osimhen go.
The threat was sent to Edoardo were handed death threats by a Galatasaray fan on WhatsApp.