Apparently it isn't the same everywhere. CA, where Dr Nick just came from, does not have such a requirement:
"Upon notification of the procedures for licensing in Minnesota that did not exist in his previous place of employment, immediate corrective actions were taken. He has since secured his unconditional license and is now in full compliance with state regulations."
It's worth pointing out that the state board might have been a bit sleepy too and made a bunch of calls all at once, since trainers for the Twins, Wolves and two from the Vikings were all applying within that March/April timeframe.