PSG beat St Etienne 2-1 after extra-time to move into the quarter-finals as they remain on course for success on all fronts.
The capital club are currently two points ahead of Monaco at the top of the Ligue 1 table although that may change on Friday with Claudio Ranieri's side hosting Valenciennes.
However, Blanc was merely grateful he does not have to motivate his side ahead of Sunday's match.
He said: "It's possible that we'll recover more quickly because we won, even though we expended a lot of energy.
"Fortunately we won because after all the energy the players left out on the pitch, if we had lost at the end of extra-time or on penalties, it would have been very hard to pick everyone up for the match against Lille on Sunday.
"This result will certainly help us recover a little quicker."
PSG have still lost only one game all season although that was a huge shock with Evian the ones to down the defending champions.
It is an indication they are beatable although Blanc's side have dropped only nine points all season.
Sunday's opponents Lille are third, four points behind their hosts having bounced straight back from defeat against Bordeaux by beating Bastia.
Monaco too have lost just one match this campaign - Lille their conquerors - and they will go one point clear for 48 hours at least with a win against struggling Valenciennes.
The visitors are third from bottom with just two wins all season, the last of which came on November 2.
Monaco, by contrast, are on a run of five successive victories and they expect to have striker Radamel Falcao back for the match.
Ranieri said: "He was able to train normally with the squad this week. I'll have to decide. I'm going to see if he'll start or whether he'll begin the game on the bench alongside me."
Fourth-placed Bordeaux will travel to Marseille, in sixth, on Sunday which would see OM leapfrog their visitors with victory.
Nantes, in fifth, travel to St Etienne on Saturday, Reims host second bottom Ajaccio, Nice face Evian, Montpellier travel to Bastia, bottom side Sochaux meet Rennes while Toulouse host Guingamp.
The remaining game on Sunday sees Lorient host Lyon.