The two sides meet for the first leg of their last 16 clash on Tuesday night at the Emirates Stadium.
Helmer told TZ Online: “Arsenal always play well, but they are never dangerous. I would not be surprised if Bayern not only wins their home tie, but also the away game in London.
“At the moment you have to say Bayern are playing well in every competition. The coach is doing everything right, the mood in the team is superb, does the game system – and they have no injuries.”