Bayern also edged past RB Leipzig in the German Cup last week and have won their two Champions League matches under Heynckes to nail down a spot in the knockout stage with two games to spare.
"We are going into this game with a lot of self-confidence," said Bayern winger Arjen Robben. "We are not the ones under pressure. We can only be happy to be three points ahead after lying five points behind them.
"It can only get better for us."
Striker Robert Lewandowski, who missed their 2-1 victory at Celtic on Tuesday due to a minor thigh injury, could be back to face his former club, said Heynckes.
"He has trained relatively well and is not feeling any pain," said Heynckes. "It looks now he can play from the start against Dortmund."
Things could not be more different for Dortmund, who squandered a five-point lead over Bayern in a matter of weeks.
Six wins from their first seven matches were then followed by a sudden slump in form and two losses and a draw in their last three games.
Dortmund have managed only one victory in their last six games in all competitions and a 1-1 home draw in the Champions League against APOEL Nicosia of Cyprus on Wednesday underlined their current struggles.
"It is my job to give my players their confidence back," said Dortmund coach Peter Bosz. "The easiest way to do it is by winning a game again. Victory is the best medicine."
Bosz will have his work cut out if Dortmund continue to waste opportunities in front of goal. They created close to a dozen scoring chances against the Cypriots on Wednesday but were let down by poor finishing.
"Maybe the timing of this game is right," Bosz said. "At the start of the season when we were winning points, expectations were high. Maybe on Saturday fans will expect a bit less."
(Editing by Peter Rutherford)
