Manchester United should abolish any thought of qualifying for next season champions league. They Haven't really played that well this campaign to deserve a top 4 finish. Besides Aston Villa and Tottenham will stand as a hindrance. If they can secure an Europa league finish it is a good season for them. It will be much more better if they can also get to the FA cup final and eventually win it. The coach should prioritize winning the FA cup and Europa league spot, over a top 4 finish. I can bet on Tottenham that they will finish in the top 4. If they can find that their early season form, they will dislodge Aston Villa from the top 4.
There are still several games left for Manchester United to catch up on points from Tottenham and Aston Villa to qualify for the Champions League, but the chances they have are very small this season because Tottenham and Aston Villa will definitely try to maintain their position.
To even qualify for the Europa League, Manchester United have to catch up six points behind Tottenham so they will be very burdened for that.
The opportunity to reach this position is a little more difficult, but they still have a chance to fight because it is possible that Tottenham will experience defeat in the next few matches and Manchester United cannot afford to lose any more points.