According to one Romanian journalist at Tuesday's pre-match press conference, Unirea boss Dan Petrescu told the local press he believed their shock win was the result of Rangers heading into the game believing they were superior to the Champions League debutants.
However, Smith was quick to refute the claim, insisting: "I don't think that's right at all.
"I don't think we are in a position to disregard anybody and we certainly didn't think that before the game.
"We didn't play well on the evening, which is the main aspect. We didn't play the way we have done in other European games but it was not because of any disrespect for the opposition.
"We will have to do far better this time than we did in the last match we played. We didn't acquit ourselves well and it was probably our poorest European performance for a while.
"We have to make sure that we try to turn that around and play in the manner we know we can. If we can do that, we have a chance."
Petrescu has revealed he made a bet with his players that they would not pick up another point in the Champions League after their stunning victory in Glasgow but Smith refused to be drawn into any mind games.
"I hope that's the case," he smiled.
"We want to try and win the game tomorrow night and that's all that matters to us.
"We have to show the way we played in the last game wasn't typical of our performances. Certainly, we played better in the other two games than we did in that game at Ibrox."
Defeat in Bucharest would spell the end of Rangers' hopes of qualifying for the knockout stages and, for that reason, Smith refused to look beyond Wednesday's match.
He said: "We were asked at the end of the last game how we felt about qualifying and, after the way we played in that game, we can't look any further than this game.
"To take something from this game will be vitally important for us and we will attempt to do that. It will have to be a far better performance than in the previous match."
Unirea Urziceni Evens, Draw 9/4, Rangers 3/1