Silva played for the full game in City's 1-1 draw against Everton at the weekend, but reported a hamstring problem after the game and has not travelled to Dortmund with the rest of the squad.
City boss Roberto Mancini said: "It's a hamstring. We don't know if he can recover for the derby. We will try.''
Somewhat surprisingly, although the Blues will be competing for a Europa League spot in Dortmund, Mancini also claimed that he would not be resting players ahead of the key clash against United. "We are a good team. We are a good club. We want to play well tomorrow and try to win. We have brought here all the players that are available. The other players that stay at home are injured."
Although Silva has not been in great form for City this season, he is still a key player for the Citizens and will be a huge miss for them in the crucial 1st-vs-2nd clash.