Only a goalless draw or a victory will do for the Blues on Tuesday night. If they crash out of Europe's elite club competition - should their boss pay the ultimate price?
Andre Villas-Boas insists he does not accept the theory this should be a season of transition for Chelsea.
When he took over at Stamford Bridge, and more recently, the Portuguese manager has maintained that even though he is implementing his new methods and planning for the future in west London, the 2011/12 campaign had to produce a challenge for major honours.
As Chelsea started their current bad run of form, Villas-Boas pointed to the fact they were still in the running to win all four major competitions. Since then though, they have fallen further behind in the Premier League and exited the League Cup to Liverpool.
Despite the morale-boosting 3-0 win over Newcastle United at the weekend, they sit 10 points adrift of runaway leaders Manchester City at the top and it appears the feature of this campaign will be a battle to ensure automatic Champions League qualification rather than a serious league title challenge.
The FA Cup does not start until January, which means all attentions are on the Champions League – a tournament which remains the Holy Grail to the Blues and their owner, Roman Abramovich.
Defeat to Bayer Leverkusen in their previous group match means their meeting with Valencia on Tuesday is a potentially season-defining match. The Premier League side need to secure a victory or a goalless draw otherwise they will be dumped out of Europe’s elite club competition and into the Europa League.
This would mean their season - at least in terms of winning the biggest trophies they are fighting for - was as good as over at the start of December. While a victory could turn everything around, ensuring Chelsea are in the last 16 and giving Villas-Boas valuable time to resurrect their league campaign and exert his influence over a longer period, it remains to be seen what failure to progress would mean.
If Chelsea are unable to reach the knockout stages of a competition they have been within touching distance of winning in years gone by, should Abramovich pull the trigger on his boss? Or, should he keep faith in the man he trusted this summer and put this season down as a year of transition, allowing the Portuguese boss time to prepare for a better challenge next time around?
While it appears Villas-Boas has support, Chelsea fans know all too well that the unpredictable nature of the Russian oligarch means no one can be completely sure what would happen if the Valencia game did not go to plan.
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