The Blues lost 3-1 at the Parc des Princes on Wednesday night, meaning that they will have to vanquish a two-goal deficit to progress.
It is a repeat of the scoreline Chelsea faced in 2012 when they defeated Napoli 2-0 at Stamford Bridge to advance, before going on to win the competition.
"Nothing is lost yet, we have to score two goals and we're averaging a good amount of goals at home, so we have what it takes to reach the next stage," Ramires is quoted as saying by The Metro.
"We played against Napoli and we won, and now we will have 90 more minutes to play against Paris. "It's no use saying who is stronger: we have to show on the pitch that we deserve to win."
Jose Mourinho's side turn their attention to the Premier League this weekend when they host Stoke City.