'Special One' will make adjustments to his starting XI next term to allow Nuri Sahin a regular first-team place following his arrival from Borussia Dortmund
The change is to allow Nuri Sahin space on the left side of a three-man midfield.
Last season's 4-2-3-1 saw Iker Casillas in goal, a back four of Sergio Ramos, Pepe, Ricardo Carvalho and Marcelo. Xabi Alonso and Sami Khedira were holding, while Angel Di Maria, Mesut Ozil and Cristiano Ronaldo often played behind Karim Benzema.
However, the changes Mourinho is considering will not affect the defence, but it will add a twist in midfielder and up front.
It is thought that Khedira will move to the right, Alonso in the middle and Sahin on the left. Ozil, Benzema and Ronaldo will be the front three.
Kaka or Di Maria could alternate roles with German international Ozil.
The new 4-3-3, if Mourinho opts to deploy it, will likely be set up in the following formation:
Casillas; Ramos, Pepe, Riccardo Carvalho, Marcelo; Khedira, Alonso, Sahin; Ozil, Benzema, Ronaldo.