The former Lille forward has been out of action since October and had hopes of returning to first-team duties after the international break
Super Eagles striker Victor Osimhen is unlikely to be available for Napoli when the Partenopeans trade tackles with Atalanta this weekend, Soccernet.ng reports.
Osimhen has been out of action since he cupped an injury during Nigeria's 2-2 draw with Saudi Arabia in Portugal last month.
The 24-year-old forward's last match for Napoli was against Fiorentina, where he scored his sixth Serie A goal of the campaign in a 1-3 home loss on October 8.
In Osimhen's absence, Napoli won three games, drew two, and lost to struggling Empoli, which led to the sacking of French manager Rudi Garcia.
Former Napoli and Inter Milan coach Walter Mazzarri was employed on an interim basis until the end of the season.
Mazzarri's first two matches in charge are tricky away games to Atalanta and Real Madrid on October 25 and 29, respectively.
The 62-year-old tactician had hoped to have Osimhen back from injury in time for the game against Atalanta.
The Nigeria forward is close to full recovery and was back in Napoli training on Tuesday, although he trained separately from the rest of the squad.
However, according to Il Mattino via Tutto Napoli, Osimhen is unlikely to be fit enough to join the team to face Atalanta on Saturday.
The Super Eagles striker is believed to be more likely to be ready for Napoli's meeting with Real Madrid at the Santiago Bernabeu on Wednesday.
Napoli have seven points from four games in the Champions League and are second behind Real Madrid, who boast 12 points in Group C.
The reigning Serie A champions must win one of their last two games to secure qualification to the knockout rounds.
