Jurgen Klopp:
If the Liverpool boss wasn't already aware of the scale of his side's troubles, he most definitely is now.
What has happened to the Reds, and can Klopp fix it? Those are the two burning questions right now, and this defeat - and most importantly the manner of it - should set alarm bells ringing.
Liverpool have played poorly before. They've played poorly in Naples before, as it happens. But rarely have they looked as bereft as they did in the first 45 minutes tonight. This wasn't just poor football, it was poor application, poor organisation and, judging by the way they started the contest, poor preparation too.
That's on the manager and his staff, as well as the players. Whatever they're doing right now, it isn't working. This was a night which made that crystal clear.
Joe Gomez:
Gomez's return to the heart of Liverpool's defence has generally gone well this season, but he was absolutely terrorised here.
Where do you even start? The woeful attempt to play offside which allowed Osimhen to hit the post inside a minute? The dallying on the ball which would have led to a goal had it not been for Van Dijk's goalline clearance soon after? The complete inability to deal with Khvaratskhelia in the box for Napoli's third goal?
It was painful to watch, Gomez sluggish, nervous and unable to get a grip of his game as Napoli went after him. He wasn't alone, by any means, but wow he was exposed here. His substitution at half-time felt like an act of mercy.
James Milner:
He's been a wonderful player for Liverpool, let's get that straight, but there's no doubt that Milner is struggling at the moment, and he certainly struggled here.
Asked to provide experience, bite and nous in midfield, he offered little of any. It was his handball which allowed Napoli to take the lead from the spot early on, he was booked for a rash lunge soon after and though there was, of course, no shortage of endeavour, he looked all of his 36 years against younger and sharper opposition.
He did well to last an hour, and it will surely be a while before he starts a game like this again.