The hosts go into the game at Signal Iduna Park just three points clear of their Bavarian rivals at the top of the table after three draws in their last six games.
Hitzfeld, who coached both clubs, does not believe that the reigning champions are cracking but he does feel that all of the momentum is with Bayern, who have won their last five matches in all competitions.
"I'm going for a draw [on Wednesday] and if Bayern were no longer in the DFB-Pokal and the Champions League, I would have tipped Dortmund [for the title]," the Switzerland boss told Spox.com.
"They are the leaders; it is they who must be overhauled. For Bayern, it is an end game and they must not lose in Dortmund. The end of the season is fast approaching, so slip-ups are no longer acceptable.
"Dortmund has a remarkable record and are unbeaten since the sixth round of the Bundesliga. And just because you sometimes draw games, this is not a sign of nervousness.
"The Bavarians have more to lose. Another year without a championship would be a disaster for Munich.
"But due to their recent success there is enormous excitement at Bayern. They can still win three titles, which spurs them on. They are confident and focused. This will make the difference."
How do you stay up to date with football when on the move? With http://m.goal.com – your best source for mobile coverage of the beautiful game.