The Blues play their final Group E game knowing they will crash out of the competition before Christmas for the first time ever unless they win or keep a clean sheet at Stamford Bridge. Failure would pile more pressure on manager Villas-Boas, who wants Chelsea's supporters to play as big a role as their heroes.
The 34-year-old, who was part of Jose Mourinho's backroom team when Chelsea knocked out Barcelona six years ago, said: "They can have a massive impact. They will have to unite themselves. I have good memories of top European nights at this club, and I know the atmosphere can be raised here, just like we did in the 4-2 against Barcelona."
He added: "If they do that, we would have the right ambience to take on Valencia with that extra input."
Chelsea need everyone pulling in the same direction and Villas-Boas admitted he had banished Nicolas Anelka and Alex from his first-team squad because their commitment to the cause could not be guaranteed.
He said of the duo, who have both submitted transfer requests: "The players are not being treated like criminals. It was discussed with with the board and the players.
"Their professionalism and integrity will never be in doubt, but we want the right mindset.
"For players on the transfer list, the reality is that, eventually, the mindset is not the same."
Villas-Boas shrugged off Frank Lampard's petulant reaction to being substituted during Saturday's Barclays Premier League win at Newcastle, saying: "Frank is a top professional and every player wants to spend more time on the pitch.
"But the manager decides things for the team. The manager makes the decision."
Source: PA
Source: PA