I don't even think they'll do much in this match other than defend and try to play it safe by going for a draw.
To get full points with Napoli as opponents is definitely not something easy to do especially the difference in their strength is very pronounced in terms of players so I doubt Genoa will do this match to seek 3 points.
Napoli still need points to revive their momentum when they lost the previous week to Lazio so in the match later I'm sure Napoli will be at full strength especially this will be a warm-up before they finally play the first matchday in the Champions League so they will definitely do their best in the match against Genoa and 3 points are a fixed price at this time for Napoli.
The least Genoa could do is make the match a little tough for Napoli to win but a full time draw, nah I don't think it would likely happen because they can't hold Napoli for the full match not when their star player is currently in a very good form and even scored a Hat-trick for his country, this would be a consolation match for their lose against Lazio before the break and don't be suprised to see Napoli winning with a three goal difference.
When it comes to defense and attack Napoli is by far better than Genoa, they got more top quality players in their team which gives them a better chance to win and it would even help them I'm the champions league opener this season because if they win with much goals it would motivate the players to do better in the Champions league opener and i believe Oshimen would score in against Genoa maybe a brace.