The Red Devils go into the game 15 points clear of City at the summit of the Premier League, but will hope to underline their dominance with victory in front of an adoring Old Trafford crowd.
However, with his squad recently having played two games in three days off the back of an international week, Sir Alex says he will need to be careful with certain players.
|200/1||Manchester United are 200/1 to beat City 6-1 with Coral|
"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.
"The form in the league has been very good. But the international break came at a difficult time for us, in terms of preparing for the following fixtures.
"We had the game on the Saturday against Sunderland and then the Cup replay against Chelsea on the Monday, after so many of the players had played two international games.
"And the calibre of player that we have means they always play for their international teams, that's for sure."
Wayne Rooney missed the clashes with Sunderland and Chelsea earlier this week after picking up an injury on England duty, but Sir Alex says the striker should be fit.
"I've no worries about Rooney because he's needing games, he's the kind of player who has to play all the time," he added.
"With Van Persie, we have to monitor it because we still don't know all about Robin, and the kind of seasons he's had. I don't think he had a season of such intensity during his time at Arsenal, so we'll have to look at that.
"Welbeck's looking strong as well, as is Chicharito."