But Unai Emery's men go into the match with a 4-0 lead after thumping Barca in Paris and, while Luis Enrique did not rule out a remarkable turnaround, he feels PSG's lead has put progression out of the reach of the Catalans.
"PSG will pressure us worse and will not defend like Celta," he told Movistar Partidazo. "But our trust is basic.
El mejor partido para afrontar a tope de moral el reto del miércoles— Ivan Rakitic (@ivanrakitic) March 4, 2017
The best match to face with confidence our Wednesday's challenge pic.twitter.com/vOf1c59erW
"The tie is lost beforehand but in wonderful circumstances you can succeed. We'll try it until the last minute."
Saturday's win was the first match since Luis Enrique announced his plans to step down at the end of the season and Barca put on a real show, which the supporters responded to with great appreciation.
"This crowd values these players and they communicate that to them," he said.
"I've never seen a lack of attitude in my players and that's why the club is faithful and confident that we can have a comeback [against PSG] – why not?"