As if losing to Chievo Verona wasn't bad enough, here's some injury to add to the insult: Gonzalo Higuain picked up a knock late in the match and is considered a doubt to play against Sparta Prague later this week.
The nature of his injury hasn't been revealed yet, but it forced Pipita to sit out of training today, leaving him little to no time to prepare for Thursday's match. Higuain came home early from his Argentina national team duties with a hamstring injury a week and a half ago, so it's not unreasonable to guess that this injury might be related to that.
Of course, it's not terribly likely that Higuain was going to play on Thursday anyways. Sparta Prague are probably the second-best team in the group behind Napoli, but the partenopei should be fine rolling out either Duvan Zapata or Michu up top. Neither has played much for Napoli so far this season, and using the Europa League to keep them ticking over (and by extension keep Higuain healthy) seems like a good plan.
As long as Higuain doesn't miss much playing time in Serie A, it'll be OK. Napoli will need their star striker in the big moments this year, and that means helping win as many league matches as possible while chasing after a Scudetto.