Here are the teams Pep Guardiola and David Moyes have selected this evening, kick-off in Germany at 19:45 GMT.
Bayern Munich: Neuer, Dante, Ribéry, Mandzukić, Robben, Boateng, Götze, Lahm, Müller, Alaba, Kroos
Subs: Raeder, Van Buyten, Rafinha, Pizarro, Weiser, Hojbjerg, Weihrauch
Manchester United: De Gea, Jones, Smalling, Vidic, Evra, Carrick, Fletcher, Valencia, Kagawa, Welbeck, Rooney
Subs: Lindegaard, Büttner, Ferdinand, Giggs, Januzaj, Young, Hernandez
Plenty didn’t think David Moyes’ Manchester United side would still be in this tie at this stage but they battled superbly to secure a 1-1 draw in the first leg at Old Trafford.
The Premier League champions backed up that result well with an important win against Newcastle United last weekend, which gives them momentum heading into the clash at the Allianz Arena.
United can take confidence from the way Arsenal have recently played against Bayern Munich in Germany, despite the fact the current European champions have put out the Gunners over the last two seasons.
United are without Juan Mata, ineligible, and Marouane Fellaini, injured, as they head into this game and the big worry before the match related to the state of Wayne Rooney’s toe.
For United to get a result in the hostile atmosphere tonight, they need every one of the players Moyes has put his faith in to stand up and be counted.