Liverpool's German manager Jurgen Klopp gestures during the UEFA Champions League, round of 16, first leg football match between Club Atletico de Madrid and Liverpool FC at the Wanda Metropolitano stadium in Madrid on Feb 18, 2020. (JAVIER SORIANO / AFP)

WARSAW - After Champions League round of 16 clash between Atletico Madrid and Liverpool FC, The Reds coach Jurgen Klopp criticized the Polish referee Szymon Marciniak.

When a match is played in such an atmosphere, you must show your strength as a referee. And I'm not sure if there was even one yellow card for rivals. It's just ridiculous. 

Jurgen Klopp, Liverpool FC coach

On Tuesday, the team coached by Diego Simeone past the titleholders 1-0 after Saul Niguez beat Alisson Becker in the 4th minute from the close range. 

At the post match press conference, Klopp said, "When a match is played in such an atmosphere, you must show your strength as a referee. And I'm not sure if there was even one yellow card for rivals. It's just ridiculous. Already in the first half three of my players fell down on the pitch and nothing happened."

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Five minutes before the break, Sadio Mane got a yellow card and in the second half he was replaced by Divock Origi. "I was afraid that the rivals would fall over as soon as Sadio took a deep breath. They did everything to send him off. He was their target. I didn't want to take a risk," explained the German.

In the interview with British BT Sport, Klopp warned the rival, "It's half time of the tie and we are 1-0 down. We don't only play a second half, we play it in our stadium which is obviously completely different to this stadium here. Our people will be ready, I know that. Welcome to Anfield, it's not over yet."