What is likely to happen now?

A high performing and a low performing Sanchez loses the ball at a similar rate. Check the statistics and you shall see that. What needs to happen is his negatives need to be handled in a way the mitigate their impact on the team. At the risk of this becoming another stick which Jose Mourinho gets beaten with, the problems Sanchez are facing can be boiled down to problems with the system. The football philosophy employed by Mourinho and the role Sanchez plays in said philosophy just do not serve the best interests of Sanchez and thus the team suffers. He needs a system that allows him to be on the ball in and around the opponent’s penalty box.
Ultimately, something has to give. The chances of Mourinho changing his philosophy to accommodate Sanchez in a manner that will see the best of the Chilean return currently look very slim. But at the same time how much longer can Mourinho continue with him being an undisputed starter? At the rate things are headed the sweetest tune Sanchez will play at United will be the one from the video that announced his signing.