Jurgen Klopp refused to blame Adrian for Liverpool's loss to Atletico Madrid, but admitted the goalkeeper's mistake had a "big impact".
Liverpool's Champions League defence came to an end on Wednesday after a 3-2 extra-time loss at Anfield sealed a 4-2 aggregate success for Atletico.
But the Premier League giants appeared on track for the quarter-finals after goals from Georginio Wijnaldum and Roberto Firmino, only for a poor clearance from Adrian to lead to Marcos Llorente's goal for Atletico.
Llorente added a second before Alvaro Morata's late sealer as Liverpool were beaten at home in the Champions League for the first time since 2014.
Despite Adrian's mistake, Klopp was unwilling to blame the shot-stopper, but said the 33-year-old was aware of his error.
"He's a man and he knows that's how it is," the Liverpool manager told a news conference.
"We will not blame him for a second – what you do, I don't know, but stay respectful, that would be really nice because he didn't want to do that, he saved us in so many moments when he played. Since he's here, he had super performances.
"This goal didn't help tonight but that's how it is. I said, if you lose a game you always lose for some [different] reasons. Tonight, this was not the moment when we lost the game, but it had a big impact.
"We should not say it was not like this because it was obvious, but that's it. We conceded more goals after that and we didn't score the goals in other situations. We had plenty of reasons why we didn't go through.
"How it is in life, especially when your job is in public, people judge you. But he's a man, a grown man, and he will deal with that. We will help him with that but I don't think he needs it, to be honest."