you bring up a good point....but if you know something about concussions(im a quasi-expert--i work with a lot of concussed people)
there is a time after the initial concussion where the healing process has things in place--proper spinal fluid pressure,brain/barrier factors are OK---but this situation is very very tenuous. Some of the neuros that I have talked to say that it takes years for this healing to stabilize.
So to throw a guy in a game again after a few weeks.......well- he may perform quite well for a game--possibly two.But ANY josling,ANY hits,ANY sudden stops and starts or even just the throwing motion can knock that delicate healing process out of wack.-And then the individual is worse than when he started.And if its a hard hit he takes then he is worse off than after the initial concussion and more brain damage can occur.-
The SD game showed what a healthy trent could do---and that is be a decent,overly careful,kinda weak armed QB.After that game he turned into a joke-and I don't think he was a joke before the concussion...overly careful and trentative--but not a joke.