Sky Sport Italia reports Victor Osimhen trained individually but Tiemoue Bakayoko has returned to train with the rest of the Napoli squad.
Good news for the Partenopei coach Gennaro Gattuso, as Bakayoko, who had reportedly developed a fever and sat out training this week, returns to the fold ahead of the match against his former club Milan.
Osimhen, who returned injured from international duty with Nigeria, worked separately and is not expected to make it in time for Sunday’s match.
Bakayoko, who was linked with a return to the Rossoneri this summer, moved on loan from Chelsea to the Azzurri and has since played four Serie A games for Napoli.
The 26-year-old has appeared six times in total, including the two games in the Europa League this term.
League leaders Milan travel to the San Paolo on Sunday, three points clear of Napoli after seven games.