Finally, Napoli fired Rudi Garcia. 
It makes sense, Rudi Garcia never improved Napoli performance. We even heard a rumor about bad relationship with the players. This will have no solution, firing him is the best decision.
I'm surprised Napoli hired Mazzarri. I think there is no very special thing with Mazzarri when he was the manager of Napoli in 2009 until 2013. The only thing that he can achieve with Napoli was winning Italian Cup in the season 2011-2012. But Napoli may have no alternatives for the coach, so they decided to sign Mazzarri.
It is very unfortunate Conte rejected the offer.
It makes sense, Rudi Garcia never improved Napoli performance. We even heard a rumor about bad relationship with the players. This will have no solution, firing him is the best decision.
I'm surprised Napoli hired Mazzarri. I think there is no very special thing with Mazzarri when he was the manager of Napoli in 2009 until 2013. The only thing that he can achieve with Napoli was winning Italian Cup in the season 2011-2012. But Napoli may have no alternatives for the coach, so they decided to sign Mazzarri.
It is very unfortunate Conte rejected the offer.
I think Mazzarri has time until the transfer window in January if he can't make any changes then I'm sure he will be fired too, I understand why many coaches reject offers from Napoli or clubs from Serie A one of the reasons is that most of the clubs in this league are experiencing a financial crisis so they don't have enough budget to bring in players while the coach certainly wants to bring in several new players to help implement his strategy. Jose Mourinho is an example of this when the club couldn't do anything when he wanted new players so it only relies on existing players and the results are of course not optimal.
As you said right now Napoli don't have many options so they have to wait until next January while observing Mazzarri's performance, we know that Mazzarri's challenge is certainly not easy, somehow he has to compete with Inter and Juventus and Napoli need 8-10 points to compete. On the other hand, Juventus and Inter continue to show consistent performance so Napoli need a miracle to catch up lol, if it only competes with AC Milan, I'm sure Napoli can do it.
I think even in the last weeks we could predict to see Rudi Gacia getting fired because after winning the title in Serie A, the fans of Napoli we expecting to see their teams be in the top side of the table and keep racing to the first place of the Serie A but Gacia failed to do that.
Also, Rudi Garcia had bad relationships with some players which is a good reason for getting him fired from Napoli and now Mazzarri joined Napoli while he should make some changes and improve the team.