To the average baseball fan, catcher pop flies look like they should be very easy. They go straight up, and come straight back down, right? Wrong! Catching fly balls can be much more difficult than it looks so learning the proper way to do it is necessary. This is a skill that is often overlooked and catchers are expected to be very good at it without much practice. Catchers should practice catching fly balls as often as other position players.
For more information about learning how to correctly catch catcher pop flies check out my book Catching-101: The Complete Guide for Baseball Catchers.