As coaches, we're probably familiar with what players typically do when they get to the field.
They will typically go right to the ball bucket, grab some baseballs, and start throwing.
When players are younger, that's probably not much of an issue, but as they start to get older, and their bodies change, it becomes important to have them warm up properly. That warmup needs to happen BEFORE they start throwing.
Don't throw to warm up...warm up to throw.