Even with those problems, they managed to draw with Barcelona. I don't think Barcelona have any serious problems that prevent them from winning, at least they are playing better than Napoli. Napoli are awful this season, as their play shows, I'll be surprised if they go any further
Both team are having poor results in matches, but let's start from Barcelona, they're ranking 3rd position on La Liga table. Barcelona manager, Xavi Hernandez will leave at the end of the season, but he still have work to do with the present team. Napoli president, Aurelio De Laurentiis have sacked his current coach, Rudi Garcia and immediately replace him with Francesco Calzona. He have solid plans to execute for the club and he's busy implementing down more exploring ideas. Napoli and Barcelona are experiencing difficulty this season, none of these teams stand in solid spot to win.
Barcelona case is more severe of you ask me because this team hasn't been the same for almost two years now while Napoli on the other hand were just crowned champions of Italy and don't really know what went wrong but they seem to have spoiled everything and now with the new coach, if his system is good then Napoli can ignite that last season flare that gave them the serie A.