Was discussing the "tap on the head" trope with my sister who is a doctor and works in neurosurgery the other day, and she listed some of the likely outcomes in terms of brain damage when you've had a blow on the head that cause maybe an hours blackout and the weeks of rehabilitation that often follow. For a week... Even today, with all the medical expertise there is, few people come out of that even relatively unharmed. We're talking all sorts of effects, and that is provided they somehow miraculously survive at all due to all the other problems mentioned with a medieval setting...
Henry VIII got a blow to his head during a joust and was out for almost an hour, IIRC (could be slightly less, could be slightly more). His recovery was pretty miraculous and rightly thought of as such by his contemporaries who had the context of 16th century experiences of blows to the head.
Quoting from
this page (just googled very quickly) on traumatic brain injury:
Traumatic brain injury (TBI) can significantly affect many cognitive, physical, and psychological skills. Physical deficit can include ambulation, balance, coordination, fine motor skills, strength, and endurance. Cognitive deficits of language and communication, information processing, memory, and perceptual skills are common. Psychological status is also often altered.
Note that this isn't necessarily talking about anything even near the brain damage associated with a week long coma.
You may want to rethink the nature of the injury. A person may be gravely wounded & effectively non-communicative for an extended period without being comatose and without making their recovery in the absence of modern medicine completely implausible.
This.
I think we underestimate injury and how incapacitating it can be with pain, and shock and blood-loss, not to mention that that infection and fever not unusually followed. If you are going for realism, you should probably investigate your other options.