If you have to put "not to be a jerk" in front of a post - you shouldn't make the post. You don't want to be a jerk yet you are saying a kid will probably never contribute any meaningful playing time to the team after he has played in one exhibition game his freshman year in college when he is already younger than the other freshmen. You say this because he is a walk-on.
Coach won't play someone just because they have been here for a while and were a walkon at one time. If he is playing quality minutes as an upperclassman that would mean he has worked hard and bettered himself to a point where he is earning those minutes. Why go out of your way to discourage people from being impressed by him and thinking he *may* be able to get quality minutes in the future? If Bubu puts as much effort into getting better as you are into making sure people don't have hope for him he will be a starter next year.