The Gabon international, who has scored seven league goals, did not train on Thursday and Tuchel said the knock on his calf was painful.
"It will be very tight, super tight," Tuchel told reporters. "Yesterday he did not train and just jogged.
"If he manages to train today then he will play tomorrow. Maybe we will even make an exception and wait until tomorrow.
"He just has a knock on the calf, no muscle injury. Yes, it's painful and yes it affects him but you could play without making it worse."
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Tuchel, who will also likely be without Portuguese Raphael Guerreiro, said winger Andre Schuerrle, recovered from his injury, could be in the squad against their bitter rivals after having trained with the team the past two days.
"It seems that two sessions may be enough for Andre to return to the squad," he said.
Dortmund have slipped down the table to sixth place after failing to win any of their last three league games. They are on 14 points, six off leaders Bayern Munich.
"It is the derby of all derbies in Germany," Tuchel said. "We know the situation, we are not happy with the results so far. We could have won some matches but did not use our chances and have to live with the consequences," he said.
"Now we have to push the team, give it the trust it needs and put players in a position to deliver more in order to win games. A derby is always an opportunity to turn things around."
(Reporting by Karolos Grohmann; Editing by Rex Gowar)
