John Terry's injury is not as bad as expected he dislocate an elbow, not break an arm, so will be OK for Moscow. Drogba should be fit too, he has ten days to recover.
Man Utd have a poor record head to head with Chelsea. They have only beaten them twice in their last six meetings. They lost the FA Cup final to Chelsea last season.
You can also figure that Chelsea will be made to feel much more at home in Russia than Utd given that Chelsea is owned by Roman Abramovich, one the worlds wealthiest people who is Russian and make sure his team is well looked after.
Grant’s record against Man U: 1 win / 1 loss
I think Jose Mourinho, the ex-Chelsea manager, had a good record against Man U.
Chelsea might have a “home-field” advantage...