he has shown he is a good keeper, and had he not made those mistakes in the CL , I bet my life the vast majority of fans wouldn't have asked for a new GK.
There was a very small minority on this forum ( myself, Scottbot, 7-KK-7, Chats(or Shabs) and maybe a couple of others) and outside that saw faults and felt we could uprade, but a vast majority that was very happy with Karius
It wasn't a small minority, it was a fair number unhappy with him after about 4 games of his career here, and wanted him out at the end of his first season, let alone last.
As he was signed by Klopp, he got every chance to learn, recover, improve, and establish himself as No. 1. Jürgen didn't want to replace him and didn't want to pay anything close to a world record fee for a goalkeeper. However, now his error rate is rising and he's struggling with the basics. So Klopp has finally run out of patience and decided to act.
Karius has two more games left before taking up that long term vigil that goalkeepers do, on the bench. But at this stage, I wouldn't even put him through the games against the mancs, then see him concede a hatful and read the reaction he gets. I would put Kelleher in, and let him stake a claim for the League Cup spot. What have we got to lose? If he does well great, if he doesn't the result doesn't matter anyway.