[Denvercoder9]

It's probably not a formal on call where people are required to be available, just a list of people that are willing to jump in if they can.

[bluedino]

Imagine 19 other people being 'too busy' to go to an NHL game with a small chance to play goalie.

[hirvi74]

It's more like 19 being too busy to be at the game in first place on the infinitesimal chance you get called up.