It was an injury crisis that gave teenager Marcus Rashford the opportunity too show Man Utd fans he was ready for the big stage. Mason Greenwood should have a similar opportunity. With his great close control and deft passing with either foot, he would be a good fit as a false 9 with Rashford at left forward and Lukaku at right forward. Physically, he could be Rashford's twin so I don't think he will be overwhelmed by EPL level defenders. I've seen all I want too see of Sanchez and Mata.