Roberto Di Matteo's side needed a last-minute winner from Victor Moses to beat Ukrainian champions Shakhtar Donetsk at Stamford Bridge on Wednesday and Luiz believes that anything other than another European triumph will be considered a failure for the club.
"If we win the Champions League again this season we will be better. Otherwise this Chelsea team are going to get worse," Luiz told reporters.
"Results show that this is a different team now. We are playing differently but we are still going to show what we can do.
"Last season our aim was the trophy and we did it. If we do it again, then we'll look at what we did differently."
One of the club's summer recruits, Brazilian starlet Oscar, scored a wonderful goal from 45 yards against Shakhtar and the youngster feels that in the context of the group, a win was absolutely vital to their chances of progression to the knockout phase.
"It was as difficult as we were expecting. We knew they were coming with an open game plan, and to try and put some pressure on us," Oscar told reporters.
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"But it was a great match and we got a very important win."
When asked what he thought of the goal, Oscar understandably sounded pleased with his effort, before praising the strength of the opposition and warning that they could cause Juventus problems when they meet next.
He added: "Yes, I think it was a beautiful goal. They let themselves down at the back, but then we haven't done ourselves any favours in defence, either.
"And that's how Shakhtar play. They are very good in attack and we struggled with that.
"That'll make it hard for Juventus too. They are a good team and everybody needs to watch out for them. But luckily we were at our best and were able to get the win."