Andre Villas-Boas admitted speculation over his future would only intensify after Chelsea lurched to yet another defeat in that left them in danger of Champions League elimination.
Villas-Boas watched his Blues side produce their latest defensive horror show to lose their last-16 first leg 3-1. The Portuguese has repeatedly insisted he has the full backing of billionaire owner Roman Abramovich but Tuesday night's performance would have done nothing to convince the Russian to deliver the vote of confidence his manager now needs.
"Speculation will continue as the results don't happen," Villas-Boas said.
Having thrown away leads with alarming regularity both at home and abroad this season, Chelsea duly did so again as captain John Terry's injury absence continued to tell.
Juan Mata gave them the dream start but all three of Napoli's subsequent goals were the result of poor defending, even if Edinson Cavani's second carried suspicions of handball.
Villas-Boas said: "We have to solve these mistakes at the back. We need this concentration right and this efficiency right, for sure.
"At the moment, without John, a very important player for the team, we have suffered a lot of goals recently.
"We had improved a lot at the beginning of January, so we have missed John. But we have full belief in these players and we have to continue to work with them to get it right."
Villas-Boas is bound to face criticism for his decision not to start either Frank Lampard or Michael Essien. Much has been made of the Chelsea boss' relationship with Lampard in particular, but he insisted his team selection was purely tactical, while Ashley Cole did not start after only just recovering from injury.
"You can have your opinion but it was based on what was the best team in my thoughts," Villas-Boas said. "Whatever explanation I give you, in the end it would be a fantastic explanation if we'd won the game. Any explanation is now useless given the result of the game, so there's no point."