Alisson was signed by Jurgen Klopp's side in the summer in the hope he would provide more reliable cover in goal, with his transfer fee of £67m ($84m) - then a world record for a shot-stopper - reflecting how much the Anfield side valued him.
He may feel differently after allowing Leicester back into the game on Saturday. The Foxes trailed 2-0 when Kelechi Iheanacho stole the ball off him and set up Rachid Ghezzal to reduce the arrears of Claude Puel's side.
Liverpool concede their first goal of the season and Leicester are back in this one! pic.twitter.com/nBAPmEYEx2— NBC Sports Soccer (@NBCSportsSoccer) September 1, 2018
It was an error that set up a tense conclusion to the match and had Reds fans casting their minds back to Karius in Kiev.
Unsurprisingly, certain corners of Twitter were quick to laugh.
Alisson B̶e̶c̶k̶e̶r̶ Karius— Deluded Brendan (@DeludedBrendan) September 1, 2018
Karius watching that Alisson blunder like pic.twitter.com/Qp7qrXom8I— Goal (@goal) September 1, 2018
We did say!🤣🤷🏼♂️ https://t.co/8y4PimCmmQ— Alan Shearer (@alanshearer) September 1, 2018
Seriously, though. Can we get Alisson checked for concussion after the game?— Paddy Power (@paddypower) September 1, 2018
Karius: "I walked alone."— Troll Football (@TrollFootball) September 1, 2018
Alisson: "You never walk alone." pic.twitter.com/CVUtTXPiXE
That Cruyff turn didn’t quite come off!— Chris Kamara (@chris_kammy) September 1, 2018
Nevertheless, some Liverpool fans are urging patience with their new keeper.
First time Alisson has made a mistake that's led to a goal since he came to Europe, by the way. Support him.— Empire of the Kop (@empireofthekop) September 1, 2018
If he does it again, though, expect a less sympathetic reaction.