The Nigerian forward was involved in an aerial clash with Nerazzurri defender Milan Skriniar that meant he had to be substituted in the second half.
Osimhen was visibly groggy as he departed the pitch and clearly had a cheek injury. As was explained by a statement from Napoli, Osimhen was operated on by Gianpaolo Tartaro on Tuesday morning to rebuild his cheekbone.
He will remain under observation for a few days and is not expected back in action for 90 days. The injury is a major blow to Napoli’s Scudetto hopes as Osimhen has been involved in seven goals in 11 Serie A appearances this season.