Yeah...it's certainly true that there is a degree of concussion that would require a player to sit out the season...but I get the impression it's really, really hard to tell that early in the recovery process. We see it all the time...the guys who get serious concussions that actually cost them months of playing time (Westbrook, from baseball Morneau) never think they're going to be out with concussion symptoms for as long as they actually wind up being out for.
Does HH have a long history of serious concussions? That's the only situation that I'd think a concussion turns into an immediate IR trip for a guy for medical reasons.