The Champions League has always been somewhat of a "Holy Grail" for Roman Abramovich, and for Andre Villas-Boas, it has perhaps become the insurance policy that could keep him in a job.
The league title seems out of reach now and, although Chelsea are still competing in the FA Cup, the Champions League run may define AVB's tenure as Blues manager.
But a huge obstacle lies in his way before he can even think about reaching the quarterfinals in the form of Napoli.
The Italian club has seen a resurgence since their back-to-back promotions after near-bankruptcy and represent a serious threat. Just ask Manchester City fans!
Here are six tactical decisions that the under-pressure Villas-Boas needs to get right if Chelsea are to survive their trip to the Stadio San Paolo with a chance of progressing to the next round.
Away trips to Italy are renowned for the hostile atmosphere and the heightened emotions of the Italian football fans that wear their club's pride on their sleeve.
The Stadio San Paolo is especially representative of this tradition, and the 60,000-capacity crowd will not constitute an environment for the faint-hearted.
Bearing this in mind, AVB should opt for the more experienced players in his squad, as some of his youthful talents could be overawed by the occasion and the vehemence of the home support.
In situations like these, Chelsea need to look to their senior players, even if their form has not been satisfactory of late.
Drogba, Lampard, Terry, Cole and Cech should all feature, and Villas-Boas needs to stress the fact that they need to inspire the younger players with their conduct on and off the pitch.
Chelsea's defense this season has suffered from a litany of mistakes and bad communication, something that they cannot afford to let happen in Italy.
The signing of Gary Cahill looks like it may prove a sound investment, but for a model of defensive solidarity, Villas-Boas should look to the home victory over Valencia.
On that day, the centre backs were playing a deeper line to accommodate for their own lack of pace, and it worked like a treat, with chances for the Spanish side coming few and far between.
With the pace of Edinson Cavani and Ezequiel Lavezzi up front for Napoli, the defense needs to be deployed deeper to prevent the South American strike partnership from getting in behind and converting chances.
Fernando Torres has been misfiring in front of goal for far too long now, and the striking instinct that once made him one of the most feared poachers in England seems to have deserted him.
In a Champions League tie of this magnitude, Didier Drogba would be the better option, as he has more big-game experience at this level and still has the potential to terrorize defenses on his day.
The Napoli defense is not known for the traditionally defensive Italian style of "catenaccio," and the strength and skill of Drogba has the potential to tear them apart.
David Luiz has been erratic this season, and his presence in the Chelsea back four always leaves an uneasy air of a potential act of carelessness.
This track record means that he should not be risked at centre-back, but the fact remains that he is too good a footballer not to have on the pitch.
If he was deployed in the holding role, then he would have more of a licence to roam up the pitch, and his liberties on the ball would not run as much risk.
He could also perhaps aim to man-mark Marek Hamsik, and hence, cut off much of the supply to Lavezzi and Cavani.
Juan Mata has been a rare bright spark for Chelsea this season and has served to add a creativity to the Chelsea midfield that it lacked under Ancelotti.
Mata has scored and set up some wonderful goals this season, and he may be even more of a threat if he were deployed in the hole behind the strikers.
Playing in a similar position as David Silva does for Manchester City, Mata would have even more of a licence to roam and create havoc than usual.
Chelsea need to limit the amount of chances handed to Napoli's deadly pairing of Cavani and Lavezzi, and the best way of doing this is to play a solid midfield that will counter the likes of Hamsik, Gargano and Imler.
Whoever AVB picks in midfield may mean the difference between success and failure, and reliability should be a key component of his selection policy.
Despite my earlier comments about experience over youth, Oriol Romeu should be seriously considered, as he has shown a maturity on the ball that belies his tender age, and he rarely yields possession.
Frank Lampard should also play, as he can always be relied upon to eat up the ground and show off his box-to-box work ethic.