Hummels in contention for Nuremberg clash
Germany international Hummels has seen his season heavily disrupted by fitness issues, with the 25-year-old suffering another ankle injury in a friendly earlier this month shortly after returning from a similar problem that had kept him out since November.
But the centre-back has now returned to full training and may be in contention for the visit of Nuremberg as Dortmund look to return to winning ways in the Bundesliga.
"Mats Hummels trained normally yesterday. I'll decide on him tomorrow," Klopp said.
Dortmund bounced back from a disappointing 3-0 defeat to Hamburg last weekend with an impressive 4-2 triumph at Zenit in the UEFA Champions League last-16 first leg.
However, Klopp is not expecting a straightforward task against Nuremberg, who have lost only to runaway league leaders Bayern Munich in their last eight top-flight games.
"We want to make amends in the Bundesliga," the coach added. "Again. We want to prove ourselves against Nuremberg.
"Nuremberg have an outstanding coach in Gertjan Verbeek. His composure is very important. They also have a great team.
"I don't think any fans are expecting us to just brush past Nuremberg. They've earned a lot of respect."