Interesting debate going on here.
As someone who's worked in the medical side of things in pro football, yes it's true many coaches have gone against what Medical staff have said.
In certain cases the medical staff will have power to say no but that's often if there is serious risk to the player. It's all about risk management, no one can predict if a player will get re-injured when they go out to play.
If the medical staff gives the green light and the player turns around and says no which I think is what is happening with Micky, then there is nothing the coach can do in that case.
Players have a lot of power because it's their body, this is why concussions have taken this long to become medical/independent decisions. It's starting to shift towards medical departments now but be under no illusion that some coaches and players will still go against what they say if they are able.
Bigger debate for me is when are players going to strike for having too many games? It's time they took action for themselves given the up tick in injuries in the game. I was having this conversation with a physio at work last week.