Oh, come on? You MUST know that I don't reckon Maradona would win it on his own?
Barca might miss him, but they have plenty of talent, enough to see them challenge in the top of La Liga and CL... The same wasn't the case for Napoli in their years without Maradona. Messi's still young, a few years younger than Maradona in his best and most winning years, but he's not the same heart-beat in the team that Maradona often was.
I know full well that Napoli had qualities, as did the Argentine sides he got to the final of the World Cup, but there's plenty of evidence to point to Maradona being the undisputed talisman of every title winning side he was in.