The Blues will travel to France after suffering a costly 1-0 defeat at Crystal Palace in the Premier League on Saturday.
Mourinho questioned the qualities of his players at Selhurst Park, but he anticipates they will shake off the setback at Parc des Princes.
He said: "I don't think I need to do a lot now. Paris is the kind of match they feel comfortable to play.
"A big match, great stadium, opponents with top quality, a profile of referee that normally stops a lot, doesn't let aggression come into the game.
"I think they will be fine, they will be in their natural habitat in that match so I believe they can do a good match there."
Mourinho has repeatedly insisted this season that his players must learn to perform when the results really matter.
He suggested some Chelsea players were out of their comfort zone at Crystal Palace, just as they had been in defeats at Everton, Newcastle and Stoke earlier in the season.
"The easiest thing to do is to play well, is to perform, when you are not playing for something big," Mourinho said.
"The difficult thing is to perform when you feel the heat. Because of that some players are big and some are not so big.
"I don't think it's courage. I think it's personality qualities.
"You have players for everything and you have other players that are in their habitat in some circumstances."
Mourinho revealed striker Samuel Eto'o is unlikely to be fit for Wednesday's match and left-back Ashley Cole is definitely out.
Watch Chelsea take on PSG live on Sky Sports 1HD at 7.45pm on Wednesday.