Brendan Rodgers is certain the red-hot Atletico atmosphere influenced the decision to send off Daizen Maeda in Madrid.
The Celtic manager reckons the Japanese forward was "underserving" of a red card for a challenge on Mario Hermoso after just 20 minutes in Spain.
And Rodgers is certain referee Ivan Kruzliak was influenced by the still image of the tackle first presented to him at the pitchside VAR monitor.
"We are clearly very, very disappointed," said Rodgers on TNT Sports. "It was always going to be a challenge for us 11 versus 11 against their quality, but to get the man sent off so early after we made a good start, looked confident and ready to fight for the game...really, really disappointed with the sending off.
"I think when you see the images that the referee sees it wasn't representative of the actual challenge, both players sort of clashed feet and kicked each other so for us then to lose a man for that was going to be really really difficult."
Asked whether the atmosphere and manner in which the events unfolded influenced the red card call, Rodgers added: "There is no doubt. I don't want to go on about the officials, I've never been one to go on, you have to accept decisions but there is no doubt.
"It feels more as if it is a computer game, the constant looking at the screen. And like I say when the referee comes over to see the incident it is not a reflection of the actual challenge, it's a still with his foot up which straight away plants the seed for the referee.
"And then from there, his influence is to send the player off.
"These players gave everything. I feel for the players because we were undeserving of the red card but when it comes it's a big challenge."
