The German giants have hit a stuttering spell of form and went down 2-1 away to Stuttgart on Friday night.
We also arrive off the back of a defeat, 2-0 at Arsenal on Saturday, but are in good shape in Group H. Top of the pile with 10 points out of a possible 12, we'll be assured of finishing first if we match Real Madrid's result at APOEL.
Recalling our 3-1 victory at Wembley which got the ball rolling in Europe this year, Bosz told reporters: "I think we played well over there but did not deserve the result we got.
"But I don't think that result was a big factor in the spell we are in now. After that, we played well, we won games in the Bundesliga. In fact, playing the football that we did in London, at one of the Premier League's top teams, was impressive. But it had no further influence."
Dortmund, third on two points, five behind second-placed Real, must win if they're to keep their hopes of qualifying for the knockout stages alive and Bosz underlined at his pre-match press conference: "It is important for us to get some points, as APOEL are still in contention as well. We definitely want to win this game."
The Dortmund chief, who managed Davinson Sanchez at Ajax last season, insisted he still feels the backing of his club's fans, in spite of their recent form.
"I understand that there is upheaval," he added. "Not winning in five Bundesliga games, it is normal to have upheaval. I feel that the people here at the club understand what phase we are in and I feel the support."