Barcelona "didn't turn up" against Juventus, according to Antoine Griezmann, who has admitted that the team lacked desire and attitude in the Group G showdown.
Juve claimed an impressive 3-0 victory at Camp Nou in the Champions League on Tuesday night as Barca surrendered their 100 per cent record in meek fashion.
With both sides already safely through to the knockout stages, the Blaugrana only needed a point to secure top spot in the group, but fell behind after just 13 minutes when Ronaldo stepped up to score a penalty after being fouled by Ronald Araujo in the box.
Juve doubled their advantage seven minutes later, with Weston McKennie rising to meet Juan Cuadrado's pinpoint cross with a flying volley which beat Marc-Andre ter Stegen all ends up in the Barca net.
All the pre-match talk centred around the renewal of hostilities between multiple Ballon d'Or winners Ronaldo and Lionel Messi, who hadn't played against each other since the former's move to the Allianz Stadium from Real Madrid in 2018.
Ronaldo put his long-time rival in the shade by converting another penalty early in the second half, with Messi ultimately enduring a night to forget after failing to score with his seven shots on goal.
Griezmann, who led the line for Barca and came closest to scoring for Koeman's team when he headed a Messi free-kick onto the crossbar shortly after Ronaldo's second goal, was in no mood to offer any excuses for the defeat after the final whistle.
The Frenchman conceded that the hosts only started playing once the game had slipped away from them, before expressing a desire to move on quickly ahead of a La Liga clash against Levante on Sunday.
"We didn't turn up," Griezmann told reporters post-match. "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.
"We are going to try to put the excuses to the side. The only way is to put everything aside, through work and nothing else. We have given a very bad account of ourselves, for the fans."
Juve qualified for the round of 16 as Group G winners after outscoring Barca 3-2 during their two meetings, and can thusly look forward to a favourable draw as they continue to chase down a first European Cup triumph since 1996.
The Blaugrana will have to face off against one of the other pool winners in the next stage, with the likes of Bayern Munich, Chelsea and Liverpool all waiting in the wings.