Fans often joke that the NHL has 32-ish head coaches and that when one is fired, he just rotates to a new team.
See guys like Peter DeBoer (rotating to Dallas) and John Tortorella (adding a name to his Metropolitan Division checklist in Philadelphia) as illustrations of that point.
The NHL isn’t exactly known as a wide open, “let’s try a new guy” league, I guess is the point here.
When the Bruins fired Bruce Cassidy, many fans assumed it would be one of those coaching retreads (Barry Trotz was a common name) who would take the reins.