The Ligue 1 champions can qualify for the last 16 of the competition by avoiding defeat at Parc des Princes, but Blanc hopes that his side can shake off any lingering self-doubt following their 1-1 draw with Anderlecht in their last Group E game.
"I don't know if Olympiacos will play like they did in their home match against us, with a high defensive line and a lot of pressure on our midfielders – I doubt it," Blanc said in his press conference.
"That caused us some problems, but whether they do or they don't, we still have to be better in technical terms. We have to expect teams to use those tactics, but it could be to our advantage as playing that way leaves some space at the back.
"We need to stop conceding so many goals. We always score some – well, almost always – but we need to be more solid in defence.
"Nerves? There's always nerves. It's part of the job, starting with the stress we put on ourselves. We know what we have to do. We have been on a good run so far, but we haven't earned our qualification yet. I said that before the match against Anderlecht, and people made fun of me saying I was always nervous, but the result unfortunately proved me right."
The match gets underway at 7.45pm.