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.

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.
The lost against empoli was the key point why rudi is getting sacked. The management has lost their confidence on him caused by lost against empoli was unacceptable result. I was also getting surprised as that was also collapsing my bet too.
That's why i really hate rudi. So many times napoli was always losing against small team and this is also making many bettors feel bad with it. Napoli has found someone to replace him but the new coach is also in the same level as rudi.
napoli may struggle till the end of season. Im not expecting a lot from mezzarri at this moment. Even though mezzarri will become an appointment till the end of season.
I don't even know why does napoli always recruit the horrible coach to manage the club.
Maybe I always see things differently from most of you, especially when a club is facing their tough times, many often entirely blame the coach which is often not the issue, the issue is more psychological than you think. I wouldn't call Rudi Garcia a horrible coach but rather say Napoli itself is facing a horrible moment this season and I believe this next coach will not do a miracle unless the players are also cooperative. Let's see what Walter Mazzarri will do in this situation, even if there is an improvmenet, it can't be signicant unless the players show willingness and start connecting too. I knew this would happen when Luciano Spalletti left at the time when the ovation was the loudest, he was a wise man that must have suspected a situation like this but claimed it was for another reason.
Napoli is not the club I envisaged could sustain their feat of last season, and if you would agree with me, the initial performance of the team earned them the scudetto last season, not the latter performance. This is a club that didn't get close to this title in 33 years, so it doesn't baffles me, not even if Luciano Spalletti is still the manager. Of course, there is no complete exoneration for such a bad performance to the point that the very low-level club like Empoli beat them and used them to promose itself from the regelation zone. But still, I believe those players need to believe well in themselves to replicate the last glory. Victor Osimhem, Khvicha Kvaratskhelia and the likes need to replicate what they did back then, not only about the coach.