Klopp: Dortmund coping despite injury crisis
Klopp's side, second in the Bundesliga but 20 points behind runaway leaders Bayern Munich, welcome Borussia Monchengladbach to Signal Iduna Park on Saturday.
But injuries have hit Klopp's team hard throughout the campaign, and they will be without the likes of Reus (muscular), Blaszczykowski (knee), Neven Subotic (knee), Sven Bender (groin) and Ilkay Gundogan (foot).
Klopp has been happy with how his side have coped without key players and urged them to build on those displays.
"We still have a difficult situation with our injured players so we can't choose from a full squad," he said on Friday.
"But I'm extremely happy with the way the team has coped with that situation, including last Sunday against Freiburg. We want to repeat that.
"Playing against us on Saturday will be a challenge indeed."
Monchengladbach have slipped to eighth in the table after a seven-match winless run, but coach Lucien Favre earned a contract extension until 2017 despite their poor form.
Klopp is wary of Favre's side and knows what they are capable of, especially in attack.
"They have huge quality. Negative results are just a small part of the whole picture," Klopp said of Saturday's opponents.
"At the end of a matchday we look at the table then we see who got points added, but that doesn't affect the strength of a team.
"(Monchengladbach midfielder) Juan Arango for example, if you let him shoot that is a mistake. If you let him a shoot a lot then you make a big mistake.
"Or if you let (Max) Kruse come into a good position, give him space, then you have also made a huge mistake.
"And Raffael is an outstanding player as well – just to name their offensive potential."