If Vesuvius had erupted during the match and sent its molten lava rolling down the hillside to engulf the old San Paolo stadium, the archaeologists of a future generation might have unearthed the remains of a youngish man, charred scraps of a rather fussy belted raincoat clinging to a corpse frozen for all time in a strangely contorted position, perhaps crouched down on its haunches, its hands fashioning an urgent gesticulation.

The historians would have noted the anguish on the man's features and assumed it to be the result of the shock and pain caused by the lava flood, like the victims in nearby Pompeii almost 2,000 years ago. They would be wrong. André Villas-Boas's pain was all caused by his football team, or rather his difficulty in making his players function according to his blueprint.

In their 3-1 defeat at the hands of Napoli, at least Chelsea were not as utterly hopeless as another London side in a different part of Italy last week. Chelsea scored an away goal, one which may yet turn out to be significant, although you would not rate their chances of turning the tie round much very higher than Arsenal's, given the counterattacking skills of Napoli's Edinson Cavani and Ezequiel Lavezzi, the scorers of all the home side's goals.

Now Villas-Boas will have to beware the Ides of March. On 14 March, the eve of the Ides, his team face Napoli again in the return leg, and in the view of much of the outside world he now has exactly 90 minutes to save his "project" and prove to the many sceptics that, at 34 years old and with very little serious experience, he is capable of managing a side at this level. Failure would make the following morning's conversation with Roman Abramovich a very difficult one.

Naturally Villas-Boas leavened his disappointment with a reaffirmation of his belief in the three-year plan undertaken at the owner's behest. In his eyes, the club's vision of a fresh future remains undimmed. "We have our idea very focused on the future," he said, "but we have to understand that we are committed to the present."

The names on the team sheet suggested that he was prepared to gamble continued progress in this season's Champions League on his desire to continue the process of weeding out some of the squad's senior figures. With John Terry ruled out on Monday night and Ashley Cole relegated to the bench, with only two days' training after returning from a calf strain, the manager made the resonant decision to leave another vastly experienced England international among the substitutes. Frank Lampard would not have taken easily to the idea of being demoted in favour of Florent Malouda, whose form this season has been so consistently dismal that most of the fans at Stamford Bridge cannot wait to see the back of him.

By contrast with Lampard, who always expects to be picked, Fernando Torres probably saw it coming. His lamentable scoring record gave him no right to expect a starting place in a match so important to the club's short-term prospects and Didier Drogba's return from the Africa Cup of Nations made it logical for the Spanish forward to stand down. The Ivorian, who will almost certainly be heading for Shanghai after his contract expires this summer, was given the captain's armband, an implied endorsement of the geeing-up he gave his team-mates against Birmingham at the weekend.

All day the schoolchildren of Naples had been parading the streets of the old city in masks and costumes to celebrate Carnevale, and their footballers started the match as if they were planning to confirm the impression they made on Manchester City by enjoying a pre-Lenten feast of attacking football and goals. Although they allowed their visitors to take an early lead, the three goals they went on to score constituted a restatement of the qualities they showed against the Premier League leaders earlier in the season.

Chelsea's rearguard, with the untempered combination of David Luiz and Gary Cahill at its heart, were never up to coping with the combination of Cavani and Lavezzi. Napoli may be lying only sixth in Serie A, with a mere nine wins in 24 matches this season, but El Matador and El Pocho (or Tubby, as Lavezzi is known) tend to make the most of the scope offered them by English defences.

Villas-Boas could take a little comfort from his side's spirit, which was certainly superior to Arsenal's, but the decision to invite Lampard to start the game on the bench will be closely scrutinised and heavily criticised.

The manager suggested that he had done it because he needed two primarily defensive midfielders in front of the back four, yet Napoli had enough chances to double their score.

"Whatever the explanation, it would be fantastic if we won the game," the manager said in words that could one day provide the epitaph for his time at Chelsea. "Any explanation now is useless, given the result."