The visitors to Signal Iduna Park have been the surprise package in the Bundesliga this season, and sit fourth in the table behind Bayern Munich, BVB and Bayer Leverkusen.
The two sides drew 3-3 in the enthralling reverse fixture in September, and Klopp believes the reigning champions’ opponents this weekend will be difficult to beat.
"I cannot recognise any sign which suggests they are going to suffer a collapse," Klopp told reporters on Friday.
"Frankfurt are playing an incredibly good season. The way they turn defence into attack is excellent, and they have Alex Meier who is having what seems to be the 47th second wind of his career.
"It is going to be a tough task for us."
Lone striker Robert Lewandowski will miss the match due to suspension, and Klopp refused to be drawn on which forward would replace the in-form Pole.
"I have a few options in my head," he added. "But I am not going to reveal them yet.
"We will find a solution, and whoever it is enjoys our full faith."
Dortmund sit 15 points behind league leaders Bayern with 13 games left to play.