Pope was sent off in Saturday's 2-0 defeat to Liverpool for inadvertently handling the ball outside his area.
Speaking at the club's media day, Howe revealed that Newcastle have not appealed the red card, leaving them with a goalkeeping dilemma ahead of the final against Manchester United.
Howe said: "No, we didn't appeal. As much as I felt sorry for Nick, and felt that the red card was really harsh for what he did, abiding by the rules, we didn't think it worth appealing."
Martin Dubravka came off the bench to play the remainder of Saturday's contest, but the Slovakia international is cup-tied after he played for Newcastle's final opponents during a loan spell with the Red Devils earlier this season.
With Karl Darlow on loan at Championship side Hull City and unable to be recalled, Howe will have to choose between Karius or Mark Gillespie for the Wembley showpiece.
Karius is widely associated with the two mistakes he made during Liverpool's 3-1 Champions League final defeat to Real Madrid in the 2017-18 season.
It proved to be Karius's last performance in a Liverpool shirt as he headed out on loan to Besiktas and Union Berlin, before joining Newcastle on a free transfer last September.
The 29-year-old has not played a competitive game since representing Union in a 1-1 draw against Hoffenheim in February 2021.
With Karius potentially set to make his Newcastle debut in Sunday's EFL Cup final, Howe has backed the German to change the narrative of his career.
"It would be a magnificent chance for him to rewrite the story of his career," Howe told reporters.
"There have been loads of stories through the times in football where these things have happened and there is been a really positive outcome or not. We cannot predict what that will be."
"As soon as it happened [Pope's dismissal against Liverpool] it was almost that feeling that there's another story in Karius's career - another page or chapter to write and who knows what that chapter will look like?
"That is the beauty of football. We never know what is going to happen. This unpredictability is what makes it such an amazing thing to watch.
"I had a chat with him on Saturday night, I felt the need to connect with him and speak with him. He was great, very relaxed. That's the kind of guy he is, a very cool customer."
Newcastle will be aiming to win their first trophy since the Fairs Cup in 1969 when they face Man United at Wembley on Sunday.