Ziggy Stardust
Master Debater
This was the exact scenario I knew about but I wasn't sure if they signed like 1 day contracts quietly or were allowed to just bc they were team employees.
Sometimes it is team employees (like that one time with Ranford at practice), other times it is someone who is just subbing in (I think they've even used some former Junior Kings goalie in the past).
The one-day contracts are tryouts that are signed by amateurs to serve as a backup in an emergency situation, which happened to the Ducks this season. They signed a goalie with RHI experience to serve as backup for that game.
http://nhl.si.com/2013/04/05/rob-laurie-jonas-hiller-nhl-ducks-goalkeeper/