The Ligue 1 leaders went down to a Cristiano Ronaldo double and Marcelo's effort in the first instalment of their round-of-16 tie, leaving them with a 3-1 deficit for the return at the Parc des Princes on March 6.
Having amassed a 12-point lead domestically, it has previously been suggested that a dearth of competition at home leads to PSG being relatively unprepared on the continent.
But they can have no such complaints this time, hosting fierce rivals Marseille twice in the space of four days in league and cup action.
And Emery hopes to get the fans onside in those games, which are PSG's only home fixtures between now and Madrid's arrival.
"We know how important the fans are," he told a news conference.
"When we are on the pitch we need all the fans in the stands and all the ones watching the game also.
"They help us by supporting us. That's why I think it is a very important time in the season.
"We have the Ligue 1 game on Sunday against Marseille, in Coupe de France against Marseille also and then the second leg here against Real Madrid.
"We'll play in the Parc, that's why I think that the club, the players and all the staff ask all the fans to be with the team. We want them to make the "Parc" a difficult stadium for all our opponents."