Probably, both teams will start the game playing cautious. Bayern has an advantage of one goal, while for Man Utd will be enough to win 1-0. So, the English side will count on the fact that they can score this goal anytime and Bayern on the fact that they can defend. But, I think this will be only the beginning of the game. The things could co crazy, and 1 goal for any team will make the game very spectacular.
Man Utd will play without Rooney, so scoring tonight will be a difficult job for them. However, I don't like Bayern defense and I think players like Nani, Berbatov or Valencia can score at least one goal. Then, Bayern needs to go in attack while Man Utd will get a lot of counter attack chances. Depending of the first goal minute, we can see in this game at least 3 goals.
Probable teams:
Manchester United: Van der Sar, G. Neville, R. Ferdinand, Vidic, Evra, Fletcher, Carrick, Valencia, Nani, Berbatov, Park Ji-Sung
Bayern Munich: Butt, Badstuber, Demichelis, Van Buyten, Lahm, Ribery, Schweinsteiger, Van Bommel, Robben, Olic, Muller.