Celtic boss Brendan Rodgers felt Luis Suarez should not have had a penalty in his side's Champions League defeat to Barcelona.
The Scottish champions are out of Europe with a game still to play in Group C after going down 2-0 at home on Wednesday courtesy of Lionel Messi's double - a first-half volley and a spot-kick after the break.
Rodgers disagreed with the decision to award Barca a spot-kick for Emilio Izaguirre's challenge on his former Liverpool striker Suarez 10 minutes into the second half and rued Moussa Dembele's missed header shortly before the incident when the deficit was only one.
He said at his post-match media conference: "I didn't think it was a penalty. I thought that Luis is brilliant at provoking defenders around the box. He is leaning into Emilio, who has tried to fight for his space. Luis is brilliant at grabbing hold of the defender and going to the ground.
"It was a key moment in the game, as we were getting into the game. At 1-0 we were always in the game. So to go 2-0 down after missing the header was disappointing. The referee didn't give us much during the game, but that's how it goes sometimes.
"What this level introduces to you is the key moments, and it shows you when moments arise in the game you have to take them.
"We got into good areas over the course of the game, some of our play was very good, but we lacked that little quality.
"It [Dembele's chance] is more difficult when you see it again - it was just behind him - but these are moments that he will learn from. I thought overall we played well enough, and hope we learn to do better and take the chances when they come."
Rodgers felt Mikael Lustig performed well in his battle with Neymar throughout the match, with both players booked after squaring up late in the game.
The Brazil international was visibly angry with Lustig and received a rough reception from the home support when he was substituted after avoiding punishment for another challenge on the defender.
Rodgers added: "It was a tough night for both players. I thought Mikael was excellent.
"You can't stand off and watch Neymar, so Mika had to be aggressive, to fight, and I think he did that. And Neymar reacted to that.
"I thought the referee did make some strange decisions throughout the course of the game. Overall, it was a clean game, we were aggressive and they had big quality, and I think in that battle Mika did very well."