People really need to get over the supposed 'mental health issues' Sancho had/has. If he mentally can't handle playing for United then he needs to leave ASAP. He can't handle the scrutiny of playing for a club of this size, that's where any of his issues stem from, and having 'issues' doesn't mean you can be an absolute dick, not run, not train right and publically call your boss a liar. United are in a results based business and you can't carry passengers in this environment because they don't like being told what to do because it makes them 'feel bad'.
Sancho has been given every opportunity to succeed at United and he has failed to take any of the chances given to him. Let's not forget that this manager gave him 5 months away from the pressure of playing for United to get himself right, if he still isn't right then what do we do now? Give him a full season away? Maybe 2 full seasons away?