#4 The Lukaku and Sanchez partnership
Romelu Lukaku has had a decent first season at United, scoring 27 goals in 50 matches. He is a big and strong centre forward, capable of out-muscling the opposition defenders. Sanchez on the other hand, is nimble-footed and very agile. They complement each other very well and their combination could trouble Chelsea a lot.
Sanchez has been a proven performer for Barcelona and Arsenal. He is new to the United set-up but has plenty of big match experience. He also has the knack of dropping down to the midfield or moving to the wings during games.
Therefore, United should give him a free role and allow him to trouble the Chelsea defence at will. He is likely to play some vital one-twos with Lukaku to create holes in the Chelsea defence, this could be a crucial combo.