PSG, who had already secured their fifth straight title, were beaten 2-1 by local rivals Paris FC on Sunday, and Luis Enrique said it was clear that motivation was an issue.
"Nothing positive to say about this match," he told reporters.
"When you play football without ambition or intensity, this is the sort of thing you’d expect to see.
"I knew before the match how difficult it would be to play this sort of game with no objective, but I’m a bit disappointed."
PSG are not in action again until May 30th when they defend their Champions League crown in the final against Arsenal.
"I think my players need to overcome difficult matches and stay motivated," the Spanish manager added.
"The final part of the season will be more complicated than usual because last year we played in the French Cup final and that was very motivating for us.
"But there are still two weeks to go before what I’d call the most important match in our history, and I certainly hope that by that day, there’ll be no need to motivate the players."