I'm not a doctor, but sure thing is hearing "herniated disc" is not something you take lightly, in general.
Maybe there have been medical advances since, but all the people I know who suffered from it, it was something that don't go away.
And back in the days, when they performed surgeries, it was disc fusion, which is debilitating because the person loose some movement capacity. Which is no good for a pro athlete.
But, at the end of the day, NHL teams have access to all sorts of medical specialists. So if they don't seem to bother, why would we?