Klopp backs Karius for Newcastle final despite previous nightmare
Karius, 29, joined Newcastle on a short-term contract in September but has yet to make his debut for the northeast club.
But that could come at Wembley a week on Sunday where Newcastle will be seeking their first major domestic trophy in 68 years.
Newcastle's first-choice keeper Nick Pope is no longer available after being sent off for handling outside his area during the high-flying Magpies' 2-0 loss at home to Liverpoolemier in the Premier League on Saturday.
Back-up Martin Dubravka is cup-tied after already appearing for Manchester United in this season's League Cup.
Karius last made a competitive appearance in Union Berlin's 1-1 Bundesliga draw with Hoffenheim in February 2021.
But he is best known in England for a calamitous display during Liverpool's 3-1 defeat by Real Madrid in the 2018 Champions League final.
He was blamed for the first and third goals Liverpool conceded, throwing the ball straight to Karim Benzema in the 50th-minute before somehow allowing a Gareth Bale shot to evade his grasp.
Karius was in floods of tears at the end of the game in Kyiv, although a subsequent medical examination indicated he had had suffered a concussion from an elbow to his head, reportedly from Sergio Ramos, minutes before his first mistake.
Liverpool boss Klopp said at the time that Karius' performance was "100 percent influenced by his concussion", however the keeper never played for the Reds again.
Klopp, speaking after Saturday's match, was asked if Karius had the mentality to handle another appearance in a final.
"I have no doubt about that," said Klopp. "He's a great goalie, that's why Newcastle signed him."
Newcastle manager Eddie Howe said Karius' involvement in major matches had been a key factor in the decision to bring him to St James' Park.
"That was the reason for taking a player of his profile," said Howe. "He has experience of the big games, so I've got no doubt or issue over his ability to step in."
Pope saw red after misjudging Alisson Becker's clearance and handling in his attempt to prevent Mohamed Salah from reaching the ball.
"Nick's very disappointed, understandably, as we are for him," said Howe. "He's been magnificent this season for us and he doesn't deserve to miss the game, but it is what it is."