Jurgen Klopp's side have struggled this term, with a recent revival enough to take them 10th going into the international break.
Bayern, meanwhile, look on course for a third straight championship - leading Wolfsburg by 10 points after Pep Guardiola's side were beaten by Borussia Monchengladbach at the weekend.
Despite the pair not being title rivals this term, the presence of former Dortmund players Mario Gotze and Robert Lewandowski at Signal Iduna Park next weekend will likely add spice to the occasion.
"I have contact with Mario, we're texting sometimes. But ahead of such a game there's no more contact than usual," explained Bender.
"Of course, it's not the same situation like it was in last years where we were really close in the standings.
"I think we found our strength again. We have a good defence again and are playing successfully again. We always showed in the past that we could keep pace with them and even win.
"Everyone is looking forward to that special task. Maybe some may underestimate us and say we're not at their best level at the moment.
"It would be nice if we could show them that we're still a top team and can always surprise."
Bender returned from a long-term knee injury recently, with his comeback coinciding with an upturn in Dortmund's fortunes.
"I wasn't able to do anything only for two weeks. After that I could start with the rehab," the Germany international added.
"All in all, it was four weeks and after that I felt really good. Of course, after this the rhythm was missing a little bit but I felt good and I am feeling good right now.
"Since my return I made every training session and I'm in top condition. Although I need the international break to train and work every day to get the final tuning that is still missing."
