The 33-year-old has spoken of his willingness to assist the young Super Eagles striker settle at Stadio San Paolo
The Nigeria international has undergone medical examinations with the Parthenopeans and it is believed a deal of around €81 million is close to being agreed.
The forward’s transfer was delayed after he changed his agent and expressed fears regarding racism in Italy but having received advice from Senegal international Kalidou Koulibaly, he then made up his mind to join the side.
The deal is expected to be wrapped up in a few days which will make the 21-year-old the most expensive Nigerian player in history.
The forward scored 18 goals and provided six assists in 38 appearances across all competitions and scooped a number of individual prizes for his efforts.
Mertens has been with the Stadio San Paolo outfit since 2013 and he is the club’s all-time scorer with 125 goals in 320 appearances.
The prolific striker, who was part of the Belgium national team that finished third at the 2018 World Cup in Russia, has expressed his willingness to help the young Super Eagles forward adapt to life at the club.
“Of course yes [I will help Osimhen]. We can also play together. Not knowing the language and the championship will take him some time, we must all be close to him,” Mertens told Radio Kiss Kiss.
Osimhen was snapped up by Lille as a replacement for Ivory Coast international Nicolas Pepe, who teamed up with Premier League club Arsenal.