Some rumors make a lot of sense, some rumors seem plausible, and some are just plain bizarre. This one tries to be plausible, but in the end it's just one of the bizarre ones.
Some time yesterday, a rumor involving Napoli cropped up. That's maybe not so weird in and of itself, considering that Napoli are a big club and this is the transfer window. The content of this rumor, though... something just didn't add up.
The talk was that Xabi Alonso, who currently plies his trade with Real Madrid and starred at Liverpool under Rafa Benitez, had been approached by Napoli and was considering joining the Italian side. On the surface, the rumor kind of made sense: Rafa likes "his" players, and Napoli have been looking for another central midfielder. Alonso's quality and experience would indicate that he should be a very good fit.
Once you start to look beyond the surface level, though, things start to fall apart fast. Yes, Napoli are looking for a central midfielder, but they're looking for a ball-winner, a destroyer, a defensive midfielder. While Alonso does play deeper in midfield and defends well, he's not really any of those things. He's a deep-lying playmaker, much like Jorginho, not the holding mid, like his old partner Javier Mascherano, that Napoli have been chasing for the last year.
Even that positional issue could be overlooked, as at least for now he represents an upgrade over Jorginho. The key words there, however, are "for now": Alonso is 32 years old and has shown clear signs of decline over the last couple of years. That coupled with his very high wages (which would make him among the highest paid Napoli players, if not the highest) mean that signing him would make less and less sense for a club trying to build for the long haul.
There's also this not-so-minor issue: Xabi and Rafa's working relationship fell apart after the manager tried to sell Alonso in order to buy Gareth freakin' Barry. While the initial move was rejected by Alonso, that did ultimately lead to him leaving the club for Real Madrid. The two have supposedly patched things up since then, but it's not hard to imagine that Alonso would be hesitant to play for Benitez again after that.
Fortunately for the sake of our brains, Alonso's agent very quickly took to the media after these reports started to circulate and rubbished any thought of a move. His client, after all, just signed a contract extension six months ago because he wanted to stay at Real Madrid. The only thing that's changed since then is that his club won the Champions League. That's not exactly a sterling reason to want to leave.
So, long story short: whole Alonso is a good player, he's a bad fit, too old, too expensive, and with other issues in hand, there's really no reason to think there's anything to this besides idle speculation. Sorry to the Napoli fans who got excited about this one: it's not happening.