Truth is, we're seeing just the tip of the iceberg when it comes to this kind of thing. There's at least one situation right now (not Crosby) where a club is very frustrated with a player's recovery from a concussion, because they think he's ready to try and he won't. The team in question believes the issue now is more psychological than real.
— That's from Elliotte Friedman's "Thirty Thoughts"
and shows just how difficult it is to deal with concussions. I'd imagine that this is especially true for players on the margins where there's an awful lot of money at stake. Alex Plante, for example, was injured while with the Oilers and earned over $130,000 for the twenty-three days he spent on the roster, most of them on injured reserve. Once he was cleared, it's back to the minors where he earns less than that over a full season. In situations like that, there's bound to be at least a little bit of skepticism on both sides.