When I was in college I worked as a referee for intramurals. We were told to always be on the lookout for the rare participant who thought it would be fun to have a few drinks before playing. Particularly in broomball, which is played on ice wearing sneakers, alcohol consumption can make for a deadly evening.
Today, I suspect it’s more common for that rare participant to show up high rather than drunk. Same idea.
It’s also possible, though much less likely, for a college athlete to make the incredibly dumb decision to show up high to practice. That type of athlete doesn’t read this blog, but you do, and you would probably notice that dumb decision before your coach does. You’re to blame if you do nothing about it.
“Coach, I think Greg was high at practice today.” Yes, you’re ratting your teammate out.
But ratting him out is better than being culpable for the destruction of the team altogether.