It was a frustrating night for Jurgen Klopp’s Liverpool at the Wanda Metropolitano last night.

A little more than eight months ago, the Reds lifted their sixth Champions League triumph in that very stadium - a triumph that appears to have taken them to the next level as they have lost just three times since.

In truth, it was a typical Diego Simeone performance from Atleti as they defended for their lives after taking an early lead and will take a 1-0 lead to Anfield.

At full-time, Klopp simply couldn’t hide his frustrations.

The German manager revealed that he had to substitute Sadio Mane at half-time because he feared Atleti would attempt to get him sent off.

"It's part of football, I don't like it," Klopp said at full-time. "The plan was to get Sadio out of the game with a yellow card.

"I was afraid that his opponent would go down if Sadio only took a deep breath. After 30 minutes, three Atletico players were on the ground, not even injured."

He went on to criticise the style of football they played.

"They got a result, the stadium wasn't here to see sensational football, they got the result and so they are happy," he said. "There are a lot of happy faces tonight from Atletico.

"It's only 1-0, we're not 5-0 down. We don't think it will be easy at our ground. For all Atletico fans who can get a ticket for the game, welcome to Anfield."

Klopp even took a dig at his opposite number, Simeone.

'I don't know if Diego saw the game because he was constantly animating the crowd,” Klopp said.

How have those comments gone down with Atleti?

Not very well, actually.

According to ESPN, Atletico Madrid players are ‘angry’ that Klopp accused them of play-acting.

The players are said to be ‘surprised’ by his comments and said it is important to be 'gracious' in defeat as well as in victory, and that Klopp should focus more on his own team's shortcomings, given that they 'didn't get a shot on target in 90 minutes'.

If the return leg at Anfield wasn’t already fascinating, it certainly is now!