Chelsea's visit to Manchester comes off the back of Thursday's 5-2 aggregate victory over Basel, while United have not played since the 1-1 draw against Arsenal at the Emirates Stadium.
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|11/1||Manchester United are 11/1 with Bet365 to draw 2-2 against Chelsea on Sunday
"We'll field a strong team because Chelsea are chasing a Champions League place," Sir Alex told reporters. "It should be a good game as we should play with enthusiasm and enjoyment."
The manager also reiterated that he has been planning next season's squad improvements for some time.
Along with Wilfried Zaha, who the club signed in January before loaning him back to Crystal Palace, Sir Alex expects "one or two" new players but expects youngsters already at the club to kick on.
"We've been [planning for next season] for a while," he added. "Your scouting goes on for the full season, actually sometimes two seasons when you maybe monitor a younger player.
"You want to see how he does the next season. That is the process we go through.
"We've got some ideas where we’re going and hopefully we can conclude them. We'll look at one or two bodies to come in.
"You've got to remember there are a lot of young players we expect to improve and take that into consideration. And you have to consider ages of players and protect that part. In the main, we know where we are. We're comfortable.
"We have fantastic strength in depth. That's the area where we don't want to confuse ourselves because you end up with too many players and trying to keep them all happy. It's happened a few times this season."