3) Arsenal’s pace up front
The North London side are not without their own injury problems, but the makeshift Man United defence they will be up against will not be able to cope with the extraordinary pace of their front line.
With Olivier Giroud out, Arsene Wenger’s attack will likely include Danny Welbeck, Alexis Sanchez and Alex-Oxlade Chamberlain, with Theo Walcott available on the bench. The sheer speed of this attack will be devastating against United on the counter.