I think ETH has handled this whole Sancho saga fantastically. Mental health is everything, you need to be totally clear in your head to be able to compete at the highest level. First you need to be able to sort out your head, after that you can focus on the physical aspects to get to the beast mode, and then - in the end - the hard work will pay off.
Rashford is a good example but vice versa. He tried to push it through injuries, but in the end if you're not physically 100%, you cannot extract from your body the effort required at this level - and he should have taken the surgery earlier when it was obvious it was needed. Playing through pain or in wrong mindset is detrimental to the team objectives.
We all know what Sancho is capable of and I hope he has beaten his demons and we will see the results on the pitch - he can be the great player we hoped he would be.