The Manchester City connection at Newcastle United which can help the club beat Manchester United at Wembley
Trippier and Karius, preparing for Newcastle United’s Carabao Cup final against Manchester United, started out with their Wembley opponent’s rivals.
Karius is set to make his Newcastle debut in Sunday’s showpiece after Nick Pope picked up a one-game suspension for his dismissal against Liverpool last weekend.
And Trippier – who has known Karius since they were teenagers coming up through the ranks at Manchester City – has no qualms about the 29-year-old, who hasn’t played a competitive game since the season before last.
"I've known Loz since Man City,” said Trippier. “I've known him since I was 15, 16.
"He’s a very good goalkeeper. He's aggressive, he's confident – and he's trained well since he's been here. He has not played games, but he’ll be ready if called upon – make no mistake about that."
Asked about their tie together at City, 32-year-old Trippier said: "We were in the youth set-up together, then we got moved up to Carrington for the reserves.
"He was a bit more advanced than I was at that time. He was more with the first team, training every day with them.
"Loz’s had a good career. You don't play that many games for Liverpool, and play in cup finals, if you're not a good goalkeeper. He was at Besiktas (on loan) as well. He's here now, so if he's playing, we have just got to support him. That's what team-mates are there for."
Martin Dubravka, Newcastle’s second-choice goalkeeper, is cup-tied, having played in the competition while on loan at Old Trafford earlier this season.
Karl Darlow was loaned to Championship club Hull City last month, and Trippier said: "This is football.
"We need everybody. Everybody has to be ready. It's crazy how it's all happened with Martin being cup-tied, Darlow going – and Popey being suspended. It gives somebody else an opportunity now to step up – and try and help the team win a trophy."
Karius’ only appearance for Newcastle so far this season came in December’s 5-0 friendly win over Al Hilal in Riyadh.