The Germany international missed last week's win over Ingolstadt due to illness, while he is still struggling with a minor adductor problem.
However, Dortmund head coach Thomas Tuchel stressed that forward Reus is raring to go in Berlin.
"Reus has been training without any problems and can play on Saturday," Tuchel said at a news conference.
"I expect a difficult game. Hertha are on a good run, but we are confident we can win there. We are ready for it.
"We can take a huge step in the right direction against Hertha and are really looking forward it."
Dortmund have a busy schedule in the coming month with matches in the Bundesliga, DFB-Pokal and Europa League to contend with, but Tuchel is confident they can manage the busy workload.
"It is important that we continue on this path and remain hungry," he added.
"We are prepared for an intense month ahead. We will do everything within our power to keep everyone healthy.
"The next six weeks or so will be very intense. It will not always be nice, but we are ready for it."