Chelsea host PSG in the second-leg trailing their round of 16 tie 5-2 on aggregate.
"I think this week has been difficult for us, but we know our strength, we know the players we have here and we still believe," said Pedro.
"We showed our power in the Club World Cup final (against PSG) – we won that game 3-0, and now we have to score three goals again.
"The group believes, the coach believes, and I think the fans should believe as well because tomorrow is going to be a great game to watch."
Pedro, on his first season in the competition, also said: "To play in the Champions League is a dream of every player.
"I have enjoyed being here at Chelsea a lot. I’m happy here.
"Against PSG, we have another opportunity to show everyone our power. Hopefully, we can win the game."