Irrespective of how small or isolated the task, you have to train them to do it. And more often than not with a junior hire, you have to re-do their work anyways, or baby-sit them the entire time while you tell them what to write.

Not to mention, that if it's something they can be trained in once and monkey-repeat ad-infinitum, then there is a near-100% chance that I can automate it.