I would say let him do what he feels like doing, at least until you see some kind of improvement with him cognitively. Of course, follow his own medical practitioners' advice over mine.

My own Dr. told me to do what I "felt like" doing... that I had to pay attention to my body and if I felt like resting to rest and if I felt like I could do something then I should do something. The biggest problem with me is that I always want to do something and I've really had to pay attention to whether doing something could cause me to overdo and that causes me to have a degrade in cognitive functioning.

Brain injuries take a lot of energy to heal from. And the body takes that energy from our reserve energy. So, people recovering from brain injuries just don't have the same amount of physical energy, or mental energy. So then when we try to do things, we tucker out super fast. In addition to our brains creating new neural pathways and healing, just the use of the new ones can take more energy than the old ones, so that's even another reason why we tucker out - the neural detours just take more energy to use.

I hope this all makes good sense.

At the same time, a healing brain does best with a structured schedule. Same time to bed, same time to rise, same time for meals etc. is a very good way to help the damaged brain to heal and manage.