The Nigeria international and Super Eagles forward will resume training with the Serie A champions on Wednesday (today).
The Partenopei were already 12 points clear going into the second half of the season and only expanded that lead to 13 points thanks to this hard-fought victory and the crumbling form of Milan.
The Partenopei have topped the league standings for much of this season and have lost just one game so far.
Reports from Italy claimed that the Partenopei would be prepared to let Nigeria international hitman Osimhen go this summer, but not for less than €110m.
Despite battling with injuries throughout his time at the Partenopei so far, the 23-year-old has scored 26 goals in 58 competitive matches since his arrival in Naples in September 2020.
The Partenopei returned to the pitch four days after their defeat in a Coppa Italia Round of 16 tie against Fiorentina.