This is a serious one
RVP for Falcao (Rooney), Carrick for Blind, Blackett for Rojo and Smalling for Jones if needed. We still lack numbers in defense and midfield. And Kagawa
Welbeck is gone? Januzaj is a tough one, he can sub on for Di Maria, Herrera, Mata, Rooney or Falcao but none of it is his best position
So, a little overcomplicated diamond that can be transformed to a 3-5-2 without the subs if needed (Blind dropping back as a ball-playing CB, fullbacks pushing farther forward) and to 4-3-3 (Mata as a SS and Di Maria-Blind-Herrera in midfield)