“It felt like something hit him and that’s not a good sign,” said Klopp.
“He will not be ready for Wednesday.”
The 26-year-old former Roma player was replaced by new signing Adrian, a free agent in the summer after he was released by West Ham.
The Spaniard made a great save from Moritz Leitner but conceded a goal in the 64th minute when Temmu Pukki fired in for Norwich.
Klopp added: “Adrian was completely relaxed and did what he had to do. He’s a good keeper, calm on the ball and a good shot stopper. That’s why we signed him.”
Liverpool’s third-choice keeper Caoimhin Kelleher is recovering from minor surgery on a broken wrist.