Barca went into the last game of the Group Stage as group leaders, knowing that they could only be leapfrogged to the top spot if the Bianconeri bettered their 2-0 away win at the Allianz Stadium.
In the end, Juve succeeded, securing a 3-0 victory at the Camp Nou in comfortable fashion, with Barca's domestic struggles oozing into their previously promising European form.
Griezmann, who recorded a 6.6 FC Rating for his performance in the game, reckons Barca didn't do much right on the night.
"We didn't turn up," the Frenchman said afterwards.
"In the first half, they got the better of us. It was a lack of everything: of desire, of attitude, willingness to run, all of it was bad.
"In the second half, there was already a three-goal advantage and it was easier for us but we had a bad day and a bad game.
"Who else can be blamed if we are the ones who play? We have to work on this and want to improve, want to play, and only in this way are we going to move forward.
The World Cup winner goes on to say that only hard work will pull them out of their current funk.
"We are going to try to put the excuses to the side," Griezmann continued.
"The only way is to put everything aside is through work and nothing else. We have given a very bad account of ourselves, for the fans."
Barcelona's domestic form under new head coach Ronald Koeman has been catastrophic so far, as they have now lost as many games as they have won (4) following the defeat against newly promoted Cadiz at the weekend.
They are currently in ninth place, 12 points off top spot in La Liga.