Nigeria and Napoli face an anxious wait over the fitness of Victor Osimhen after the striker suffered fractures to his cheekbone and eye socket in the 3-2 defeat by Inter Milan on Sunday.
The 22-year-old, who is Napoli's top scorer this season with nine goals in 14 appearances, was substituted in the 52nd minute following a nasty clash of heads with Inter's Milan Skriniar.
Italian Serie A leaders Napoli confirmed the extent of the injury on Twitter, adding that the forward "will undergo surgery in the next few days".
With just seven weeks until the start of the Africa Cup of Nations in Cameroon, top officials of the Nigeria Football Federation (NFF) are keen to know whether Osimhen will be fit for the continental showpiece event.
"It's a major concern but we cannot comment about Osimhen until we hear from the club," an NFF official told BBC Sport Africa.
"Hopefully there will be some positive news after his surgery."
Nigeria will open their campaign for a fourth continental title on 11 January against the tournament's most successful nation Egypt.
The defeat by Inter was Napoli's first of the league season and the potential long-term absence of Osimhen comes as a blow to their quest for a third Serie A title.
Reports in the Italian media suggest the surgery to repair damage to his left eye and the surrounding region could sideline him for at least six weeks.
"We've not been able to speak to him in Italy but we've been told by the club that he needs to rest," a source close to the player told BBC Sport Africa.
Napoli's top scorer this season with five Serie A goals and four in the Europa League, Osimhen netted four times in six games to help Nigeria to reach Africa's World Cup play-offs next March.
He also finished as joint-top scorer in qualifying for the delayed Nations Cup, with five goals.