United have had a busy schedule of late and Fergie knows that he has to be careful when picking his sides over the holiday period and the time leading out of it.
The United boss is keen to add to the 15 point lead that they hold over neighbours Man City in the league and he also knows that if United don't lose, it will almost certainly mean they will be picking up the Premier League Trophy come May.
But some players will have to be rested; the boss just has to figure out which ones.
"These are the games that everyone wants to be involved in, the derby games," Ferguson told Inside United.
"Over the last few years the derby games have been far more important than they ever were, so we've all been looking forward to them. But we've had a heavy programme leading up to the game so we just have to manage it."
Source: United Mad