Sheyi Ojo, 18, marked his substitute's appearance by becoming the youngest goalscorer in Liverpool's FA Cup history, while Teixeira and Joe Allen also netting to set up a fourth-round clash against West Ham United.
Klopp praised his makeshift team, but cautioned fans to be patient about the youngsters' prospects in the Premier League, where Liverpool are languishing in ninth place, eight points off the Champions League spots.
"They showed what they are able to do and showed what they still have to learn. Now it is about giving the lads time to develop, not protecting them," Klopp told reporters after the game.
"There are a lot of things to learn. The target at the end of the road is Liverpool FC in the Premier League and for this you have to be ready in all parts of development."
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The German was particularly pleased to welcome back defender Jon Flanagan, who made his first appearance for the club since the end of the 2013-14 season after twice undergoing knee surgery.
"The whole stadium stood up and clapped their hands. It was really good and nobody deserved it more than him. It's such a long time, an unbelievably long time," Klopp said.
"Since I've been here he was always injured -- but never in a bad mood. That's unbelievable. He's a really strong lad."
(Reporting by Simon Jennings in Bengaluru; editing by Amlan Chakraborty)
