Loris Karius has confirmed he received death threats after his Champions League final nightmare two years ago - and regrets not being more forceful in his response to criticism following Liverpool's defeat.
Asked if he received death threats in the wake of the Champions League final defeat, Karius said: "There were some of them. But I can't take that seriously.
"These are people who write anonymously and don't even show their faces in their profiles. I don't think when people walk past me personally they can't open their mouths.
"Players receive some extremely hostile messages on the internet. If you read every message, you wouldn't be able to sleep for two days.
"It's insane what people come out with under the guise of anonymity, badly insulting others, discriminating against them and then becoming racist.
"You can't blame fans if they whistle a player. They pay admission and have the right to be dissatisfied. A professional has to endure that.
"But if there are personal insults or death threats, the limit is far exceeded."
Karius, speaking in a lengthy interview with Sport Bild, admits he should have been more forceful in his public reaction to the criticism he received.
"Believe me, I've learned a lot from that!" he added. "In retrospect, I should have dealt with it publicly much more aggressively. I had a concussion after a blow from Sergio Ramos, which restricted my spatial vision.
"When the result was released, there was a lot of malice and insult, often well below the belt. I never used it as an excuse. But when people make fun of someone who has badly injured their head, I have no understanding.
"The reactions were over the top and disrespectful. My mistakes were not assessed fairly."
Karius hasn't played a competitive game for Liverpool since the Champions League final defeat to Real Madrid and is unlikely to play for the club again.
But the German has revealed he remains in constant contact with the Reds, and said: "I primarily write with goalkeeper coach John Achterberg. Almost weekly, he is my first point of contact.
"But now and then I also write with Jurgen Klopp, I am in good contact with everyone. I was never out of it.
"The fact is that I have a contract in Liverpool until 2022. And at the moment I'm just concentrating on the season at Besiktas.
"It is far too early to say anything about summer. Especially now that nobody knows exactly what to do because of the coronavirus."