I think Barcelona should be able to beat Napoli easily and there shouldn't be any issue at all. I think the best thing to do in this case would be just assuming that it would be a good period, and we could end up with something that should benefit everyone. I get that the best thing to do in this situation would be just assuming the world is not ending, you don't have to pay everything all that easily but you just have to assume that betting on Barcelona is a great way to make some money.
I am not saying that it's guaranteed, Barcelona could still lose, not like they are having a wonderful season, but they are certainly doing much better than Napoli has been doing so it should be a win for them without a doubt.
I don't think the match against Napoli is actually going to be easy for Barcelona to be honest. Barcelona has been facing a good amount of problems this season. Napoli also has not been the best of teams lately but the thing is Barcelona also has a lot of injury problems as well. Actually, both of them are going through the same kind of problems, to be honest now that I think about it. Both of them have to defend the league title and both also have to do very well in the Champions League as well. And both have the same kind of problems except for the fact that Barca has a few injuries. Barca is falling off in the La Liga pretty badly, to be honest. So I also think Barcelona might think about giving the La Liga a better chance instead of the UCL. Anyway, I think the match against Napoli is going to be competitive.
The match between Napoli and Barcelona is the only match in the Round of 16 which will be a 50-50 chance. I mean look at both of them, Barcelona are struggling in their own league. La Liga’s bottom team is Almeria and Barcelona won against them barely with a score of 3-2. Forwards and Defence have problems in their squad. Lewandsonksi is not doing good either. They are financially not doing well either. They could have improved their squad in the January transfer market but considering their financial situation they wouldn't.
On the other hand, Napoli is also struggling. Recently lost against Napoli and are sitting in the 7th position of Serie A. They are struggling just like Barcelona and they are nowhere near their last season performance. So it will be a clear 50-50 chance between them. Either they are going to lose against their next opponent I believe.